diff --git a/src/liblzma/common/alone_decoder.c b/src/liblzma/common/alone_decoder.c
index c1360ca1..dd681765 100644
--- a/src/liblzma/common/alone_decoder.c
+++ b/src/liblzma/common/alone_decoder.c
@@ -15,7 +15,7 @@
 #include "lz_decoder.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	lzma_next_coder next;
 
 	enum {
@@ -46,17 +46,19 @@ struct lzma_coder_s {
 	/// Options decoded from the header needed to initialize
 	/// the LZMA decoder
 	lzma_options_lzma options;
-};
+} lzma_alone_coder;
 
 
 static lzma_ret
-alone_decode(lzma_coder *coder,
+alone_decode(void *coder_ptr,
 		const lzma_allocator *allocator lzma_attribute((__unused__)),
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size,
 		lzma_action action)
 {
+	lzma_alone_coder *coder = coder_ptr;
+
 	while (*out_pos < out_size
 			&& (coder->sequence == SEQ_CODE || *in_pos < in_size))
 	switch (coder->sequence) {
@@ -166,8 +168,9 @@ alone_decode(lzma_coder *coder,
 
 
 static void
-alone_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+alone_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_alone_coder *coder = coder_ptr;
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -175,9 +178,11 @@ alone_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-alone_decoder_memconfig(lzma_coder *coder, uint64_t *memusage,
+alone_decoder_memconfig(void *coder_ptr, uint64_t *memusage,
 		uint64_t *old_memlimit, uint64_t new_memlimit)
 {
+	lzma_alone_coder *coder = coder_ptr;
+
 	*memusage = coder->memusage;
 	*old_memlimit = coder->memlimit;
 
@@ -201,26 +206,29 @@ lzma_alone_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	if (memlimit == 0)
 		return LZMA_PROG_ERROR;
 
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_alone_coder *coder = next->coder;
+
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_alone_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &alone_decode;
 		next->end = &alone_decoder_end;
 		next->memconfig = &alone_decoder_memconfig;
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
-	next->coder->sequence = SEQ_PROPERTIES;
-	next->coder->picky = picky;
-	next->coder->pos = 0;
-	next->coder->options.dict_size = 0;
-	next->coder->options.preset_dict = NULL;
-	next->coder->options.preset_dict_size = 0;
-	next->coder->uncompressed_size = 0;
-	next->coder->memlimit = memlimit;
-	next->coder->memusage = LZMA_MEMUSAGE_BASE;
+	coder->sequence = SEQ_PROPERTIES;
+	coder->picky = picky;
+	coder->pos = 0;
+	coder->options.dict_size = 0;
+	coder->options.preset_dict = NULL;
+	coder->options.preset_dict_size = 0;
+	coder->uncompressed_size = 0;
+	coder->memlimit = memlimit;
+	coder->memusage = LZMA_MEMUSAGE_BASE;
 
 	return LZMA_OK;
 }
diff --git a/src/liblzma/common/alone_encoder.c b/src/liblzma/common/alone_encoder.c
index a2bc9eee..4853cfd1 100644
--- a/src/liblzma/common/alone_encoder.c
+++ b/src/liblzma/common/alone_encoder.c
@@ -17,7 +17,7 @@
 #define ALONE_HEADER_SIZE (1 + 4 + 8)
 
 
-struct lzma_coder_s {
+typedef struct {
 	lzma_next_coder next;
 
 	enum {
@@ -27,17 +27,19 @@ struct lzma_coder_s {
 
 	size_t header_pos;
 	uint8_t header[ALONE_HEADER_SIZE];
-};
+} lzma_alone_coder;
 
 
 static lzma_ret
-alone_encode(lzma_coder *coder,
+alone_encode(void *coder_ptr,
 		const lzma_allocator *allocator lzma_attribute((__unused__)),
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size,
 		lzma_action action)
 {
+	lzma_alone_coder *coder = coder_ptr;
+
 	while (*out_pos < out_size)
 	switch (coder->sequence) {
 	case SEQ_HEADER:
@@ -65,8 +67,9 @@ alone_encode(lzma_coder *coder,
 
 
 static void
-alone_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+alone_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_alone_coder *coder = coder_ptr;
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -80,23 +83,26 @@ alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 {
 	lzma_next_coder_init(&alone_encoder_init, next, allocator);
 
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_alone_coder *coder = next->coder;
+
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_alone_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &alone_encode;
 		next->end = &alone_encoder_end;
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
 	// Basic initializations
-	next->coder->sequence = SEQ_HEADER;
-	next->coder->header_pos = 0;
+	coder->sequence = SEQ_HEADER;
+	coder->header_pos = 0;
 
 	// Encode the header:
 	// - Properties (1 byte)
-	if (lzma_lzma_lclppb_encode(options, next->coder->header))
+	if (lzma_lzma_lclppb_encode(options, coder->header))
 		return LZMA_OPTIONS_ERROR;
 
 	// - Dictionary size (4 bytes)
@@ -116,10 +122,10 @@ alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	if (d != UINT32_MAX)
 		++d;
 
-	unaligned_write32le(next->coder->header + 1, d);
+	unaligned_write32le(coder->header + 1, d);
 
 	// - Uncompressed size (always unknown and using EOPM)
-	memset(next->coder->header + 1 + 4, 0xFF, 8);
+	memset(coder->header + 1 + 4, 0xFF, 8);
 
 	// Initialize the LZMA encoder.
 	const lzma_filter_info filters[2] = {
@@ -131,7 +137,7 @@ alone_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		}
 	};
 
-	return lzma_next_filter_init(&next->coder->next, allocator, filters);
+	return lzma_next_filter_init(&coder->next, allocator, filters);
 }
 
 
diff --git a/src/liblzma/common/auto_decoder.c b/src/liblzma/common/auto_decoder.c
index bf355070..09acd6dc 100644
--- a/src/liblzma/common/auto_decoder.c
+++ b/src/liblzma/common/auto_decoder.c
@@ -14,7 +14,7 @@
 #include "alone_decoder.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	/// Stream decoder or LZMA_Alone decoder
 	lzma_next_coder next;
 
@@ -26,15 +26,17 @@ struct lzma_coder_s {
 		SEQ_CODE,
 		SEQ_FINISH,
 	} sequence;
-};
+} lzma_auto_coder;
 
 
 static lzma_ret
-auto_decode(lzma_coder *coder, const lzma_allocator *allocator,
+auto_decode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_auto_coder *coder = coder_ptr;
+
 	switch (coder->sequence) {
 	case SEQ_INIT:
 		if (*in_pos >= in_size)
@@ -100,8 +102,9 @@ auto_decode(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static void
-auto_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+auto_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_auto_coder *coder = coder_ptr;
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -109,8 +112,10 @@ auto_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_check
-auto_decoder_get_check(const lzma_coder *coder)
+auto_decoder_get_check(const void *coder_ptr)
 {
+	const lzma_auto_coder *coder = coder_ptr;
+
 	// It is LZMA_Alone if get_check is NULL.
 	return coder->next.get_check == NULL ? LZMA_CHECK_NONE
 			: coder->next.get_check(coder->next.coder);
@@ -118,9 +123,11 @@ auto_decoder_get_check(const lzma_coder *coder)
 
 
 static lzma_ret
-auto_decoder_memconfig(lzma_coder *coder, uint64_t *memusage,
+auto_decoder_memconfig(void *coder_ptr, uint64_t *memusage,
 		uint64_t *old_memlimit, uint64_t new_memlimit)
 {
+	lzma_auto_coder *coder = coder_ptr;
+
 	lzma_ret ret;
 
 	if (coder->next.memconfig != NULL) {
@@ -154,21 +161,23 @@ auto_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	if (flags & ~LZMA_SUPPORTED_FLAGS)
 		return LZMA_OPTIONS_ERROR;
 
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_auto_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_auto_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &auto_decode;
 		next->end = &auto_decoder_end;
 		next->get_check = &auto_decoder_get_check;
 		next->memconfig = &auto_decoder_memconfig;
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
-	next->coder->memlimit = memlimit;
-	next->coder->flags = flags;
-	next->coder->sequence = SEQ_INIT;
+	coder->memlimit = memlimit;
+	coder->flags = flags;
+	coder->sequence = SEQ_INIT;
 
 	return LZMA_OK;
 }
diff --git a/src/liblzma/common/block_decoder.c b/src/liblzma/common/block_decoder.c
index 685c3b03..075bd279 100644
--- a/src/liblzma/common/block_decoder.c
+++ b/src/liblzma/common/block_decoder.c
@@ -15,7 +15,7 @@
 #include "check.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	enum {
 		SEQ_CODE,
 		SEQ_PADDING,
@@ -48,7 +48,7 @@ struct lzma_coder_s {
 
 	/// True if the integrity check won't be calculated and verified.
 	bool ignore_check;
-};
+} lzma_block_coder;
 
 
 static inline bool
@@ -74,11 +74,13 @@ is_size_valid(lzma_vli size, lzma_vli reference)
 
 
 static lzma_ret
-block_decode(lzma_coder *coder, const lzma_allocator *allocator,
+block_decode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_block_coder *coder = coder_ptr;
+
 	switch (coder->sequence) {
 	case SEQ_CODE: {
 		const size_t in_start = *in_pos;
@@ -177,8 +179,9 @@ block_decode(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static void
-block_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+block_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_block_coder *coder = coder_ptr;
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -198,27 +201,29 @@ lzma_block_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 			|| !lzma_vli_is_valid(block->uncompressed_size))
 		return LZMA_PROG_ERROR;
 
-	// Allocate and initialize *next->coder if needed.
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	// Allocate *next->coder if needed.
+	lzma_block_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_block_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &block_decode;
 		next->end = &block_decoder_end;
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
 	// Basic initializations
-	next->coder->sequence = SEQ_CODE;
-	next->coder->block = block;
-	next->coder->compressed_size = 0;
-	next->coder->uncompressed_size = 0;
+	coder->sequence = SEQ_CODE;
+	coder->block = block;
+	coder->compressed_size = 0;
+	coder->uncompressed_size = 0;
 
 	// If Compressed Size is not known, we calculate the maximum allowed
 	// value so that encoded size of the Block (including Block Padding)
 	// is still a valid VLI and a multiple of four.
-	next->coder->compressed_limit
+	coder->compressed_limit
 			= block->compressed_size == LZMA_VLI_UNKNOWN
 				? (LZMA_VLI_MAX & ~LZMA_VLI_C(3))
 					- block->header_size
@@ -228,14 +233,14 @@ lzma_block_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	// Initialize the check. It's caller's problem if the Check ID is not
 	// supported, and the Block decoder cannot verify the Check field.
 	// Caller can test lzma_check_is_supported(block->check).
-	next->coder->check_pos = 0;
-	lzma_check_init(&next->coder->check, block->check);
+	coder->check_pos = 0;
+	lzma_check_init(&coder->check, block->check);
 
-	next->coder->ignore_check = block->version >= 1
+	coder->ignore_check = block->version >= 1
 			? block->ignore_check : false;
 
 	// Initialize the filter chain.
-	return lzma_raw_decoder_init(&next->coder->next, allocator,
+	return lzma_raw_decoder_init(&coder->next, allocator,
 			block->filters);
 }
 
diff --git a/src/liblzma/common/block_encoder.c b/src/liblzma/common/block_encoder.c
index def58641..168846ad 100644
--- a/src/liblzma/common/block_encoder.c
+++ b/src/liblzma/common/block_encoder.c
@@ -15,7 +15,7 @@
 #include "check.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	/// The filters in the chain; initialized with lzma_raw_decoder_init().
 	lzma_next_coder next;
 
@@ -41,15 +41,17 @@ struct lzma_coder_s {
 
 	/// Check of the uncompressed data
 	lzma_check_state check;
-};
+} lzma_block_coder;
 
 
 static lzma_ret
-block_encode(lzma_coder *coder, const lzma_allocator *allocator,
+block_encode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_block_coder *coder = coder_ptr;
+
 	// Check that our amount of input stays in proper limits.
 	if (LZMA_VLI_MAX - coder->uncompressed_size < in_size - *in_pos)
 		return LZMA_DATA_ERROR;
@@ -134,8 +136,9 @@ block_encode(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static void
-block_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+block_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_block_coder *coder = coder_ptr;
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -143,10 +146,12 @@ block_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-block_encoder_update(lzma_coder *coder, const lzma_allocator *allocator,
+block_encoder_update(void *coder_ptr, const lzma_allocator *allocator,
 		const lzma_filter *filters lzma_attribute((__unused__)),
 		const lzma_filter *reversed_filters)
 {
+	lzma_block_coder *coder = coder_ptr;
+
 	if (coder->sequence != SEQ_CODE)
 		return LZMA_PROG_ERROR;
 
@@ -178,30 +183,31 @@ lzma_block_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		return LZMA_UNSUPPORTED_CHECK;
 
 	// Allocate and initialize *next->coder if needed.
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_block_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_block_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &block_encode;
 		next->end = &block_encoder_end;
 		next->update = &block_encoder_update;
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
 	// Basic initializations
-	next->coder->sequence = SEQ_CODE;
-	next->coder->block = block;
-	next->coder->compressed_size = 0;
-	next->coder->uncompressed_size = 0;
-	next->coder->pos = 0;
+	coder->sequence = SEQ_CODE;
+	coder->block = block;
+	coder->compressed_size = 0;
+	coder->uncompressed_size = 0;
+	coder->pos = 0;
 
 	// Initialize the check
-	lzma_check_init(&next->coder->check, block->check);
+	lzma_check_init(&coder->check, block->check);
 
 	// Initialize the requested filters.
-	return lzma_raw_encoder_init(&next->coder->next, allocator,
-			block->filters);
+	return lzma_raw_encoder_init(&coder->next, allocator, block->filters);
 }
 
 
diff --git a/src/liblzma/common/common.h b/src/liblzma/common/common.h
index 955d784a..b3d3b7a0 100644
--- a/src/liblzma/common/common.h
+++ b/src/liblzma/common/common.h
@@ -88,10 +88,6 @@
 #define LZMA_TIMED_OUT 32
 
 
-/// Type of encoder/decoder specific data; the actual structure is defined
-/// differently in different coders.
-typedef struct lzma_coder_s lzma_coder;
-
 typedef struct lzma_next_coder_s lzma_next_coder;
 
 typedef struct lzma_filter_info_s lzma_filter_info;
@@ -107,7 +103,7 @@ typedef lzma_ret (*lzma_init_function)(
 /// input and output buffers, but for simplicity they still use this same
 /// function prototype.
 typedef lzma_ret (*lzma_code_function)(
-		lzma_coder *coder, const lzma_allocator *allocator,
+		void *coder, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size,
@@ -115,7 +111,7 @@ typedef lzma_ret (*lzma_code_function)(
 
 /// Type of a function to free the memory allocated for the coder
 typedef void (*lzma_end_function)(
-		lzma_coder *coder, const lzma_allocator *allocator);
+		void *coder, const lzma_allocator *allocator);
 
 
 /// Raw coder validates and converts an array of lzma_filter structures to
@@ -138,7 +134,7 @@ struct lzma_filter_info_s {
 /// Hold data and function pointers of the next filter in the chain.
 struct lzma_next_coder_s {
 	/// Pointer to coder-specific data
-	lzma_coder *coder;
+	void *coder;
 
 	/// Filter ID. This is LZMA_VLI_UNKNOWN when this structure doesn't
 	/// point to a filter coder.
@@ -160,21 +156,21 @@ struct lzma_next_coder_s {
 
 	/// Pointer to a function to get progress information. If this is NULL,
 	/// lzma_stream.total_in and .total_out are used instead.
-	void (*get_progress)(lzma_coder *coder,
+	void (*get_progress)(void *coder,
 			uint64_t *progress_in, uint64_t *progress_out);
 
 	/// Pointer to function to return the type of the integrity check.
 	/// Most coders won't support this.
-	lzma_check (*get_check)(const lzma_coder *coder);
+	lzma_check (*get_check)(const void *coder);
 
 	/// Pointer to function to get and/or change the memory usage limit.
 	/// If new_memlimit == 0, the limit is not changed.
-	lzma_ret (*memconfig)(lzma_coder *coder, uint64_t *memusage,
+	lzma_ret (*memconfig)(void *coder, uint64_t *memusage,
 			uint64_t *old_memlimit, uint64_t new_memlimit);
 
 	/// Update the filter-specific options or the whole filter chain
 	/// in the encoder.
-	lzma_ret (*update)(lzma_coder *coder, const lzma_allocator *allocator,
+	lzma_ret (*update)(void *coder, const lzma_allocator *allocator,
 			const lzma_filter *filters,
 			const lzma_filter *reversed_filters);
 };
diff --git a/src/liblzma/common/index_decoder.c b/src/liblzma/common/index_decoder.c
index 795d1834..1e33f0b0 100644
--- a/src/liblzma/common/index_decoder.c
+++ b/src/liblzma/common/index_decoder.c
@@ -14,7 +14,7 @@
 #include "check.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	enum {
 		SEQ_INDICATOR,
 		SEQ_COUNT,
@@ -50,11 +50,11 @@ struct lzma_coder_s {
 
 	/// CRC32 of the List of Records field
 	uint32_t crc32;
-};
+} lzma_index_coder;
 
 
 static lzma_ret
-index_decode(lzma_coder *coder, const lzma_allocator *allocator,
+index_decode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size,
 		uint8_t *restrict out lzma_attribute((__unused__)),
@@ -62,6 +62,8 @@ index_decode(lzma_coder *coder, const lzma_allocator *allocator,
 		size_t out_size lzma_attribute((__unused__)),
 		lzma_action action lzma_attribute((__unused__)))
 {
+	lzma_index_coder *coder = coder_ptr;
+
 	// Similar optimization as in index_encoder.c
 	const size_t in_start = *in_pos;
 	lzma_ret ret = LZMA_OK;
@@ -207,8 +209,9 @@ out:
 
 
 static void
-index_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+index_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_index_coder *coder = coder_ptr;
 	lzma_index_end(coder->index, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -216,9 +219,11 @@ index_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-index_decoder_memconfig(lzma_coder *coder, uint64_t *memusage,
+index_decoder_memconfig(void *coder_ptr, uint64_t *memusage,
 		uint64_t *old_memlimit, uint64_t new_memlimit)
 {
+	lzma_index_coder *coder = coder_ptr;
+
 	*memusage = lzma_index_memusage(1, coder->count);
 	*old_memlimit = coder->memlimit;
 
@@ -234,7 +239,7 @@ index_decoder_memconfig(lzma_coder *coder, uint64_t *memusage,
 
 
 static lzma_ret
-index_decoder_reset(lzma_coder *coder, const lzma_allocator *allocator,
+index_decoder_reset(lzma_index_coder *coder, const lzma_allocator *allocator,
 		lzma_index **i, uint64_t memlimit)
 {
 	// Remember the pointer given by the application. We will set it
@@ -269,20 +274,22 @@ index_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	if (i == NULL || memlimit == 0)
 		return LZMA_PROG_ERROR;
 
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_index_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_index_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &index_decode;
 		next->end = &index_decoder_end;
 		next->memconfig = &index_decoder_memconfig;
-		next->coder->index = NULL;
+		coder->index = NULL;
 	} else {
-		lzma_index_end(next->coder->index, allocator);
+		lzma_index_end(coder->index, allocator);
 	}
 
-	return index_decoder_reset(next->coder, allocator, i, memlimit);
+	return index_decoder_reset(coder, allocator, i, memlimit);
 }
 
 
@@ -309,7 +316,7 @@ lzma_index_buffer_decode(lzma_index **i, uint64_t *memlimit,
 		return LZMA_PROG_ERROR;
 
 	// Initialize the decoder.
-	lzma_coder coder;
+	lzma_index_coder coder;
 	return_if_error(index_decoder_reset(&coder, allocator, i, *memlimit));
 
 	// Store the input start position so that we can restore it in case
diff --git a/src/liblzma/common/index_encoder.c b/src/liblzma/common/index_encoder.c
index d25ac7d3..ac97d0ce 100644
--- a/src/liblzma/common/index_encoder.c
+++ b/src/liblzma/common/index_encoder.c
@@ -15,7 +15,7 @@
 #include "check.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	enum {
 		SEQ_INDICATOR,
 		SEQ_COUNT,
@@ -37,11 +37,11 @@ struct lzma_coder_s {
 
 	/// CRC32 of the List of Records field
 	uint32_t crc32;
-};
+} lzma_index_coder;
 
 
 static lzma_ret
-index_encode(lzma_coder *coder,
+index_encode(void *coder_ptr,
 		const lzma_allocator *allocator lzma_attribute((__unused__)),
 		const uint8_t *restrict in lzma_attribute((__unused__)),
 		size_t *restrict in_pos lzma_attribute((__unused__)),
@@ -50,6 +50,8 @@ index_encode(lzma_coder *coder,
 		size_t out_size,
 		lzma_action action lzma_attribute((__unused__)))
 {
+	lzma_index_coder *coder = coder_ptr;
+
 	// Position where to start calculating CRC32. The idea is that we
 	// need to call lzma_crc32() only once per call to index_encode().
 	const size_t out_start = *out_pos;
@@ -159,7 +161,7 @@ out:
 
 
 static void
-index_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+index_encoder_end(void *coder, const lzma_allocator *allocator)
 {
 	lzma_free(coder, allocator);
 	return;
@@ -167,7 +169,7 @@ index_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static void
-index_encoder_reset(lzma_coder *coder, const lzma_index *i)
+index_encoder_reset(lzma_index_coder *coder, const lzma_index *i)
 {
 	lzma_index_iter_init(&coder->iter, i);
 
@@ -190,7 +192,7 @@ lzma_index_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		return LZMA_PROG_ERROR;
 
 	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		next->coder = lzma_alloc(sizeof(lzma_index_coder), allocator);
 		if (next->coder == NULL)
 			return LZMA_MEM_ERROR;
 
@@ -230,7 +232,7 @@ lzma_index_buffer_encode(const lzma_index *i,
 
 	// The Index encoder needs just one small data structure so we can
 	// allocate it on stack.
-	lzma_coder coder;
+	lzma_index_coder coder;
 	index_encoder_reset(&coder, i);
 
 	// Do the actual encoding. This should never fail, but store
diff --git a/src/liblzma/common/stream_decoder.c b/src/liblzma/common/stream_decoder.c
index 3ab938c9..7ae7a670 100644
--- a/src/liblzma/common/stream_decoder.c
+++ b/src/liblzma/common/stream_decoder.c
@@ -14,7 +14,7 @@
 #include "block_decoder.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	enum {
 		SEQ_STREAM_HEADER,
 		SEQ_BLOCK_HEADER,
@@ -80,11 +80,11 @@ struct lzma_coder_s {
 	/// Buffer to hold Stream Header, Block Header, and Stream Footer.
 	/// Block Header has biggest maximum size.
 	uint8_t buffer[LZMA_BLOCK_HEADER_SIZE_MAX];
-};
+} lzma_stream_coder;
 
 
 static lzma_ret
-stream_decoder_reset(lzma_coder *coder, const lzma_allocator *allocator)
+stream_decoder_reset(lzma_stream_coder *coder, const lzma_allocator *allocator)
 {
 	// Initialize the Index hash used to verify the Index.
 	coder->index_hash = lzma_index_hash_init(coder->index_hash, allocator);
@@ -100,11 +100,13 @@ stream_decoder_reset(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-stream_decode(lzma_coder *coder, const lzma_allocator *allocator,
+stream_decode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_stream_coder *coder = coder_ptr;
+
 	// When decoding the actual Block, it may be able to produce more
 	// output even if we don't give it any new input.
 	while (true)
@@ -375,8 +377,9 @@ stream_decode(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static void
-stream_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+stream_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_stream_coder *coder = coder_ptr;
 	lzma_next_end(&coder->block_decoder, allocator);
 	lzma_index_hash_end(coder->index_hash, allocator);
 	lzma_free(coder, allocator);
@@ -385,16 +388,19 @@ stream_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_check
-stream_decoder_get_check(const lzma_coder *coder)
+stream_decoder_get_check(const void *coder_ptr)
 {
+	const lzma_stream_coder *coder = coder_ptr;
 	return coder->stream_flags.check;
 }
 
 
 static lzma_ret
-stream_decoder_memconfig(lzma_coder *coder, uint64_t *memusage,
+stream_decoder_memconfig(void *coder_ptr, uint64_t *memusage,
 		uint64_t *old_memlimit, uint64_t new_memlimit)
 {
+	lzma_stream_coder *coder = coder_ptr;
+
 	*memusage = coder->memusage;
 	*old_memlimit = coder->memlimit;
 
@@ -422,31 +428,33 @@ lzma_stream_decoder_init(
 	if (flags & ~LZMA_SUPPORTED_FLAGS)
 		return LZMA_OPTIONS_ERROR;
 
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_stream_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_stream_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &stream_decode;
 		next->end = &stream_decoder_end;
 		next->get_check = &stream_decoder_get_check;
 		next->memconfig = &stream_decoder_memconfig;
 
-		next->coder->block_decoder = LZMA_NEXT_CODER_INIT;
-		next->coder->index_hash = NULL;
+		coder->block_decoder = LZMA_NEXT_CODER_INIT;
+		coder->index_hash = NULL;
 	}
 
-	next->coder->memlimit = memlimit;
-	next->coder->memusage = LZMA_MEMUSAGE_BASE;
-	next->coder->tell_no_check = (flags & LZMA_TELL_NO_CHECK) != 0;
-	next->coder->tell_unsupported_check
+	coder->memlimit = memlimit;
+	coder->memusage = LZMA_MEMUSAGE_BASE;
+	coder->tell_no_check = (flags & LZMA_TELL_NO_CHECK) != 0;
+	coder->tell_unsupported_check
 			= (flags & LZMA_TELL_UNSUPPORTED_CHECK) != 0;
-	next->coder->tell_any_check = (flags & LZMA_TELL_ANY_CHECK) != 0;
-	next->coder->ignore_check = (flags & LZMA_IGNORE_CHECK) != 0;
-	next->coder->concatenated = (flags & LZMA_CONCATENATED) != 0;
-	next->coder->first_stream = true;
+	coder->tell_any_check = (flags & LZMA_TELL_ANY_CHECK) != 0;
+	coder->ignore_check = (flags & LZMA_IGNORE_CHECK) != 0;
+	coder->concatenated = (flags & LZMA_CONCATENATED) != 0;
+	coder->first_stream = true;
 
-	return stream_decoder_reset(next->coder, allocator);
+	return stream_decoder_reset(coder, allocator);
 }
 
 
diff --git a/src/liblzma/common/stream_encoder.c b/src/liblzma/common/stream_encoder.c
index a7663bc4..858cba47 100644
--- a/src/liblzma/common/stream_encoder.c
+++ b/src/liblzma/common/stream_encoder.c
@@ -14,7 +14,7 @@
 #include "index_encoder.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	enum {
 		SEQ_STREAM_HEADER,
 		SEQ_BLOCK_INIT,
@@ -55,11 +55,11 @@ struct lzma_coder_s {
 	/// Buffer to hold Stream Header, Block Header, and Stream Footer.
 	/// Block Header has biggest maximum size.
 	uint8_t buffer[LZMA_BLOCK_HEADER_SIZE_MAX];
-};
+} lzma_stream_coder;
 
 
 static lzma_ret
-block_encoder_init(lzma_coder *coder, const lzma_allocator *allocator)
+block_encoder_init(lzma_stream_coder *coder, const lzma_allocator *allocator)
 {
 	// Prepare the Block options. Even though Block encoder doesn't need
 	// compressed_size, uncompressed_size, and header_size to be
@@ -78,11 +78,13 @@ block_encoder_init(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-stream_encode(lzma_coder *coder, const lzma_allocator *allocator,
+stream_encode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_stream_coder *coder = coder_ptr;
+
 	// Main loop
 	while (*out_pos < out_size)
 	switch (coder->sequence) {
@@ -209,8 +211,10 @@ stream_encode(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static void
-stream_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+stream_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_stream_coder *coder = coder_ptr;
+
 	lzma_next_end(&coder->block_encoder, allocator);
 	lzma_next_end(&coder->index_encoder, allocator);
 	lzma_index_end(coder->index, allocator);
@@ -224,10 +228,12 @@ stream_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-stream_encoder_update(lzma_coder *coder, const lzma_allocator *allocator,
+stream_encoder_update(void *coder_ptr, const lzma_allocator *allocator,
 		const lzma_filter *filters,
 		const lzma_filter *reversed_filters)
 {
+	lzma_stream_coder *coder = coder_ptr;
+
 	if (coder->sequence <= SEQ_BLOCK_INIT) {
 		// There is no incomplete Block waiting to be finished,
 		// thus we can change the whole filter chain. Start by
@@ -271,30 +277,33 @@ stream_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	if (filters == NULL)
 		return LZMA_PROG_ERROR;
 
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_stream_coder *coder = next->coder;
+
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_stream_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &stream_encode;
 		next->end = &stream_encoder_end;
 		next->update = &stream_encoder_update;
 
-		next->coder->filters[0].id = LZMA_VLI_UNKNOWN;
-		next->coder->block_encoder = LZMA_NEXT_CODER_INIT;
-		next->coder->index_encoder = LZMA_NEXT_CODER_INIT;
-		next->coder->index = NULL;
+		coder->filters[0].id = LZMA_VLI_UNKNOWN;
+		coder->block_encoder = LZMA_NEXT_CODER_INIT;
+		coder->index_encoder = LZMA_NEXT_CODER_INIT;
+		coder->index = NULL;
 	}
 
 	// Basic initializations
-	next->coder->sequence = SEQ_STREAM_HEADER;
-	next->coder->block_options.version = 0;
-	next->coder->block_options.check = check;
+	coder->sequence = SEQ_STREAM_HEADER;
+	coder->block_options.version = 0;
+	coder->block_options.check = check;
 
 	// Initialize the Index
-	lzma_index_end(next->coder->index, allocator);
-	next->coder->index = lzma_index_init(allocator);
-	if (next->coder->index == NULL)
+	lzma_index_end(coder->index, allocator);
+	coder->index = lzma_index_init(allocator);
+	if (coder->index == NULL)
 		return LZMA_MEM_ERROR;
 
 	// Encode the Stream Header
@@ -303,16 +312,15 @@ stream_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		.check = check,
 	};
 	return_if_error(lzma_stream_header_encode(
-			&stream_flags, next->coder->buffer));
+			&stream_flags, coder->buffer));
 
-	next->coder->buffer_pos = 0;
-	next->coder->buffer_size = LZMA_STREAM_HEADER_SIZE;
+	coder->buffer_pos = 0;
+	coder->buffer_size = LZMA_STREAM_HEADER_SIZE;
 
 	// Initialize the Block encoder. This way we detect unsupported
 	// filter chains when initializing the Stream encoder instead of
 	// giving an error after Stream Header has already written out.
-	return stream_encoder_update(
-			next->coder, allocator, filters, NULL);
+	return stream_encoder_update(coder, allocator, filters, NULL);
 }
 
 
diff --git a/src/liblzma/common/stream_encoder_mt.c b/src/liblzma/common/stream_encoder_mt.c
index 9780ed04..2efe44c2 100644
--- a/src/liblzma/common/stream_encoder_mt.c
+++ b/src/liblzma/common/stream_encoder_mt.c
@@ -44,6 +44,7 @@ typedef enum {
 
 } worker_state;
 
+typedef struct lzma_stream_coder_s lzma_stream_coder;
 
 typedef struct worker_thread_s worker_thread;
 struct worker_thread_s {
@@ -65,7 +66,7 @@ struct worker_thread_s {
 
 	/// Pointer to the main structure is needed when putting this
 	/// thread back to the stack of free threads.
-	lzma_coder *coder;
+	lzma_stream_coder *coder;
 
 	/// The allocator is set by the main thread. Since a copy of the
 	/// pointer is kept here, the application must not change the
@@ -96,7 +97,7 @@ struct worker_thread_s {
 };
 
 
-struct lzma_coder_s {
+struct lzma_stream_coder_s {
 	enum {
 		SEQ_STREAM_HEADER,
 		SEQ_BLOCK,
@@ -417,7 +418,7 @@ worker_start(void *thr_ptr)
 
 /// Make the threads stop but not exit. Optionally wait for them to stop.
 static void
-threads_stop(lzma_coder *coder, bool wait_for_threads)
+threads_stop(lzma_stream_coder *coder, bool wait_for_threads)
 {
 	// Tell the threads to stop.
 	for (uint32_t i = 0; i < coder->threads_initialized; ++i) {
@@ -446,7 +447,7 @@ threads_stop(lzma_coder *coder, bool wait_for_threads)
 /// Stop the threads and free the resources associated with them.
 /// Wait until the threads have exited.
 static void
-threads_end(lzma_coder *coder, const lzma_allocator *allocator)
+threads_end(lzma_stream_coder *coder, const lzma_allocator *allocator)
 {
 	for (uint32_t i = 0; i < coder->threads_initialized; ++i) {
 		mythread_sync(coder->threads[i].mutex) {
@@ -468,7 +469,8 @@ threads_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 /// Initialize a new worker_thread structure and create a new thread.
 static lzma_ret
-initialize_new_thread(lzma_coder *coder, const lzma_allocator *allocator)
+initialize_new_thread(lzma_stream_coder *coder,
+		const lzma_allocator *allocator)
 {
 	worker_thread *thr = &coder->threads[coder->threads_initialized];
 
@@ -510,7 +512,7 @@ error_mutex:
 
 
 static lzma_ret
-get_thread(lzma_coder *coder, const lzma_allocator *allocator)
+get_thread(lzma_stream_coder *coder, const lzma_allocator *allocator)
 {
 	// If there are no free output subqueues, there is no
 	// point to try getting a thread.
@@ -548,7 +550,7 @@ get_thread(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-stream_encode_in(lzma_coder *coder, const lzma_allocator *allocator,
+stream_encode_in(lzma_stream_coder *coder, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, lzma_action action)
 {
@@ -616,7 +618,7 @@ stream_encode_in(lzma_coder *coder, const lzma_allocator *allocator,
 /// Wait until more input can be consumed, more output can be read, or
 /// an optional timeout is reached.
 static bool
-wait_for_work(lzma_coder *coder, mythread_condtime *wait_abs,
+wait_for_work(lzma_stream_coder *coder, mythread_condtime *wait_abs,
 		bool *has_blocked, bool has_input)
 {
 	if (coder->timeout != 0 && !*has_blocked) {
@@ -662,11 +664,13 @@ wait_for_work(lzma_coder *coder, mythread_condtime *wait_abs,
 
 
 static lzma_ret
-stream_encode_mt(lzma_coder *coder, const lzma_allocator *allocator,
+stream_encode_mt(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_stream_coder *coder = coder_ptr;
+
 	switch (coder->sequence) {
 	case SEQ_STREAM_HEADER:
 		lzma_bufcpy(coder->header, &coder->header_pos,
@@ -834,8 +838,10 @@ stream_encode_mt(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static void
-stream_encoder_mt_end(lzma_coder *coder, const lzma_allocator *allocator)
+stream_encoder_mt_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_stream_coder *coder = coder_ptr;
+
 	// Threads must be killed before the output queue can be freed.
 	threads_end(coder, allocator);
 	lzma_outq_end(&coder->outq, allocator);
@@ -907,10 +913,12 @@ get_options(const lzma_mt *options, lzma_options_easy *opt_easy,
 
 
 static void
-get_progress(lzma_coder *coder, uint64_t *progress_in, uint64_t *progress_out)
+get_progress(void *coder_ptr, uint64_t *progress_in, uint64_t *progress_out)
 {
+	lzma_stream_coder *coder = coder_ptr;
+
 	// Lock coder->mutex to prevent finishing threads from moving their
-	// progress info from the worker_thread structure to lzma_coder.
+	// progress info from the worker_thread structure to lzma_stream_coder.
 	mythread_sync(coder->mutex) {
 		*progress_in = coder->progress_in;
 		*progress_out = coder->progress_out;
@@ -962,24 +970,27 @@ stream_encoder_mt_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		return LZMA_UNSUPPORTED_CHECK;
 
 	// Allocate and initialize the base structure if needed.
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_stream_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_stream_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
+
 		// For the mutex and condition variable initializations
 		// the error handling has to be done here because
 		// stream_encoder_mt_end() doesn't know if they have
 		// already been initialized or not.
-		if (mythread_mutex_init(&next->coder->mutex)) {
-			lzma_free(next->coder, allocator);
+		if (mythread_mutex_init(&coder->mutex)) {
+			lzma_free(coder, allocator);
 			next->coder = NULL;
 			return LZMA_MEM_ERROR;
 		}
 
-		if (mythread_cond_init(&next->coder->cond)) {
-			mythread_mutex_destroy(&next->coder->mutex);
-			lzma_free(next->coder, allocator);
+		if (mythread_cond_init(&coder->cond)) {
+			mythread_mutex_destroy(&coder->mutex);
+			lzma_free(coder, allocator);
 			next->coder = NULL;
 			return LZMA_MEM_ERROR;
 		}
@@ -989,76 +1000,76 @@ stream_encoder_mt_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		next->get_progress = &get_progress;
 // 		next->update = &stream_encoder_mt_update;
 
-		next->coder->filters[0].id = LZMA_VLI_UNKNOWN;
-		next->coder->index_encoder = LZMA_NEXT_CODER_INIT;
-		next->coder->index = NULL;
-		memzero(&next->coder->outq, sizeof(next->coder->outq));
-		next->coder->threads = NULL;
-		next->coder->threads_max = 0;
-		next->coder->threads_initialized = 0;
+		coder->filters[0].id = LZMA_VLI_UNKNOWN;
+		coder->index_encoder = LZMA_NEXT_CODER_INIT;
+		coder->index = NULL;
+		memzero(&coder->outq, sizeof(coder->outq));
+		coder->threads = NULL;
+		coder->threads_max = 0;
+		coder->threads_initialized = 0;
 	}
 
 	// Basic initializations
-	next->coder->sequence = SEQ_STREAM_HEADER;
-	next->coder->block_size = (size_t)(block_size);
-	next->coder->thread_error = LZMA_OK;
-	next->coder->thr = NULL;
+	coder->sequence = SEQ_STREAM_HEADER;
+	coder->block_size = (size_t)(block_size);
+	coder->thread_error = LZMA_OK;
+	coder->thr = NULL;
 
 	// Allocate the thread-specific base structures.
 	assert(options->threads > 0);
-	if (next->coder->threads_max != options->threads) {
-		threads_end(next->coder, allocator);
+	if (coder->threads_max != options->threads) {
+		threads_end(coder, allocator);
 
-		next->coder->threads = NULL;
-		next->coder->threads_max = 0;
+		coder->threads = NULL;
+		coder->threads_max = 0;
 
-		next->coder->threads_initialized = 0;
-		next->coder->threads_free = NULL;
+		coder->threads_initialized = 0;
+		coder->threads_free = NULL;
 
-		next->coder->threads = lzma_alloc(
+		coder->threads = lzma_alloc(
 				options->threads * sizeof(worker_thread),
 				allocator);
-		if (next->coder->threads == NULL)
+		if (coder->threads == NULL)
 			return LZMA_MEM_ERROR;
 
-		next->coder->threads_max = options->threads;
+		coder->threads_max = options->threads;
 	} else {
 		// Reuse the old structures and threads. Tell the running
 		// threads to stop and wait until they have stopped.
-		threads_stop(next->coder, true);
+		threads_stop(coder, true);
 	}
 
 	// Output queue
-	return_if_error(lzma_outq_init(&next->coder->outq, allocator,
+	return_if_error(lzma_outq_init(&coder->outq, allocator,
 			outbuf_size_max, options->threads));
 
 	// Timeout
-	next->coder->timeout = options->timeout;
+	coder->timeout = options->timeout;
 
 	// Free the old filter chain and copy the new one.
-	for (size_t i = 0; next->coder->filters[i].id != LZMA_VLI_UNKNOWN; ++i)
-		lzma_free(next->coder->filters[i].options, allocator);
+	for (size_t i = 0; coder->filters[i].id != LZMA_VLI_UNKNOWN; ++i)
+		lzma_free(coder->filters[i].options, allocator);
 
 	return_if_error(lzma_filters_copy(
-			filters, next->coder->filters, allocator));
+			filters, coder->filters, allocator));
 
 	// Index
-	lzma_index_end(next->coder->index, allocator);
-	next->coder->index = lzma_index_init(allocator);
-	if (next->coder->index == NULL)
+	lzma_index_end(coder->index, allocator);
+	coder->index = lzma_index_init(allocator);
+	if (coder->index == NULL)
 		return LZMA_MEM_ERROR;
 
 	// Stream Header
-	next->coder->stream_flags.version = 0;
-	next->coder->stream_flags.check = options->check;
+	coder->stream_flags.version = 0;
+	coder->stream_flags.check = options->check;
 	return_if_error(lzma_stream_header_encode(
-			&next->coder->stream_flags, next->coder->header));
+			&coder->stream_flags, coder->header));
 
-	next->coder->header_pos = 0;
+	coder->header_pos = 0;
 
 	// Progress info
-	next->coder->progress_in = 0;
-	next->coder->progress_out = LZMA_STREAM_HEADER_SIZE;
+	coder->progress_in = 0;
+	coder->progress_out = LZMA_STREAM_HEADER_SIZE;
 
 	return LZMA_OK;
 }
@@ -1111,7 +1122,8 @@ lzma_stream_encoder_mt_memusage(const lzma_mt *options)
 		return UINT64_MAX;
 
 	// Sum them with overflow checking.
-	uint64_t total_memusage = LZMA_MEMUSAGE_BASE + sizeof(lzma_coder)
+	uint64_t total_memusage = LZMA_MEMUSAGE_BASE
+			+ sizeof(lzma_stream_coder)
 			+ options->threads * sizeof(worker_thread);
 
 	if (UINT64_MAX - total_memusage < inbuf_memusage)
diff --git a/src/liblzma/delta/delta_common.c b/src/liblzma/delta/delta_common.c
index 13dd4682..4768201d 100644
--- a/src/liblzma/delta/delta_common.c
+++ b/src/liblzma/delta/delta_common.c
@@ -15,8 +15,9 @@
 
 
 static void
-delta_coder_end(lzma_coder *coder, const lzma_allocator *allocator)
+delta_coder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_delta_coder *coder = coder_ptr;
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -28,14 +29,17 @@ lzma_delta_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		const lzma_filter_info *filters)
 {
 	// Allocate memory for the decoder if needed.
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_delta_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_delta_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
+
 		// End function is the same for encoder and decoder.
 		next->end = &delta_coder_end;
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
 	// Validate the options.
@@ -44,15 +48,14 @@ lzma_delta_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 
 	// Set the delta distance.
 	const lzma_options_delta *opt = filters[0].options;
-	next->coder->distance = opt->dist;
+	coder->distance = opt->dist;
 
 	// Initialize the rest of the variables.
-	next->coder->pos = 0;
-	memzero(next->coder->history, LZMA_DELTA_DIST_MAX);
+	coder->pos = 0;
+	memzero(coder->history, LZMA_DELTA_DIST_MAX);
 
 	// Initialize the next decoder in the chain, if any.
-	return lzma_next_filter_init(&next->coder->next,
-			allocator, filters + 1);
+	return lzma_next_filter_init(&coder->next, allocator, filters + 1);
 }
 
 
@@ -66,5 +69,5 @@ lzma_delta_coder_memusage(const void *options)
 			|| opt->dist > LZMA_DELTA_DIST_MAX)
 		return UINT64_MAX;
 
-	return sizeof(lzma_coder);
+	return sizeof(lzma_delta_coder);
 }
diff --git a/src/liblzma/delta/delta_decoder.c b/src/liblzma/delta/delta_decoder.c
index 726d0239..6859afa5 100644
--- a/src/liblzma/delta/delta_decoder.c
+++ b/src/liblzma/delta/delta_decoder.c
@@ -15,7 +15,7 @@
 
 
 static void
-decode_buffer(lzma_coder *coder, uint8_t *buffer, size_t size)
+decode_buffer(lzma_delta_coder *coder, uint8_t *buffer, size_t size)
 {
 	const size_t distance = coder->distance;
 
@@ -27,11 +27,13 @@ decode_buffer(lzma_coder *coder, uint8_t *buffer, size_t size)
 
 
 static lzma_ret
-delta_decode(lzma_coder *coder, const lzma_allocator *allocator,
+delta_decode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_delta_coder *coder = coder_ptr;
+
 	assert(coder->next.code != NULL);
 
 	const size_t out_start = *out_pos;
diff --git a/src/liblzma/delta/delta_encoder.c b/src/liblzma/delta/delta_encoder.c
index 5a842636..38416515 100644
--- a/src/liblzma/delta/delta_encoder.c
+++ b/src/liblzma/delta/delta_encoder.c
@@ -18,7 +18,7 @@
 /// is the first filter in the chain (and thus the last filter in the
 /// encoder's filter stack).
 static void
-copy_and_encode(lzma_coder *coder,
+copy_and_encode(lzma_delta_coder *coder,
 		const uint8_t *restrict in, uint8_t *restrict out, size_t size)
 {
 	const size_t distance = coder->distance;
@@ -35,7 +35,7 @@ copy_and_encode(lzma_coder *coder,
 /// Encodes the data in place. This is used when we are the last filter
 /// in the chain (and thus non-last filter in the encoder's filter stack).
 static void
-encode_in_place(lzma_coder *coder, uint8_t *buffer, size_t size)
+encode_in_place(lzma_delta_coder *coder, uint8_t *buffer, size_t size)
 {
 	const size_t distance = coder->distance;
 
@@ -49,11 +49,13 @@ encode_in_place(lzma_coder *coder, uint8_t *buffer, size_t size)
 
 
 static lzma_ret
-delta_encode(lzma_coder *coder, const lzma_allocator *allocator,
+delta_encode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_delta_coder *coder = coder_ptr;
+
 	lzma_ret ret;
 
 	if (coder->next.code == NULL) {
@@ -84,10 +86,12 @@ delta_encode(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static lzma_ret
-delta_encoder_update(lzma_coder *coder, const lzma_allocator *allocator,
+delta_encoder_update(void *coder_ptr, const lzma_allocator *allocator,
 		const lzma_filter *filters_null lzma_attribute((__unused__)),
 		const lzma_filter *reversed_filters)
 {
+	lzma_delta_coder *coder = coder_ptr;
+
 	// Delta doesn't and will never support changing the options in
 	// the middle of encoding. If the app tries to change them, we
 	// simply ignore them.
diff --git a/src/liblzma/delta/delta_private.h b/src/liblzma/delta/delta_private.h
index 46ce0c64..0d6cb386 100644
--- a/src/liblzma/delta/delta_private.h
+++ b/src/liblzma/delta/delta_private.h
@@ -15,7 +15,7 @@
 
 #include "delta_common.h"
 
-struct lzma_coder_s {
+typedef struct {
 	/// Next coder in the chain
 	lzma_next_coder next;
 
@@ -27,7 +27,7 @@ struct lzma_coder_s {
 
 	/// Buffer to hold history of the original data
 	uint8_t history[LZMA_DELTA_DIST_MAX];
-};
+} lzma_delta_coder;
 
 
 extern lzma_ret lzma_delta_coder_init(
diff --git a/src/liblzma/lz/lz_decoder.c b/src/liblzma/lz/lz_decoder.c
index 2328a8e7..c7086440 100644
--- a/src/liblzma/lz/lz_decoder.c
+++ b/src/liblzma/lz/lz_decoder.c
@@ -20,7 +20,7 @@
 #include "lz_decoder.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	/// Dictionary (history buffer)
 	lzma_dict dict;
 
@@ -48,7 +48,7 @@ struct lzma_coder_s {
 		size_t size;
 		uint8_t buffer[LZMA_BUFFER_SIZE];
 	} temp;
-};
+} lzma_coder;
 
 
 static void
@@ -125,13 +125,15 @@ decode_buffer(lzma_coder *coder,
 
 
 static lzma_ret
-lz_decode(lzma_coder *coder,
+lz_decode(void *coder_ptr,
 		const lzma_allocator *allocator lzma_attribute((__unused__)),
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size,
 		lzma_action action)
 {
+	lzma_coder *coder = coder_ptr;
+
 	if (coder->next.code == NULL)
 		return decode_buffer(coder, in, in_pos, in_size,
 				out, out_pos, out_size);
@@ -184,8 +186,10 @@ lz_decode(lzma_coder *coder,
 
 
 static void
-lz_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+lz_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_coder *coder = coder_ptr;
+
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder->dict.buf, allocator);
 
@@ -207,24 +211,26 @@ lzma_lz_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 			lzma_lz_options *lz_options))
 {
 	// Allocate the base structure if it isn't already allocated.
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &lz_decode;
 		next->end = &lz_decoder_end;
 
-		next->coder->dict.buf = NULL;
-		next->coder->dict.size = 0;
-		next->coder->lz = LZMA_LZ_DECODER_INIT;
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->dict.buf = NULL;
+		coder->dict.size = 0;
+		coder->lz = LZMA_LZ_DECODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
 	// Allocate and initialize the LZ-based decoder. It will also give
 	// us the dictionary size.
 	lzma_lz_options lz_options;
-	return_if_error(lz_init(&next->coder->lz, allocator,
+	return_if_error(lz_init(&coder->lz, allocator,
 			filters[0].options, &lz_options));
 
 	// If the dictionary size is very small, increase it to 4096 bytes.
@@ -248,14 +254,14 @@ lzma_lz_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 	lz_options.dict_size = (lz_options.dict_size + 15) & ~((size_t)(15));
 
 	// Allocate and initialize the dictionary.
-	if (next->coder->dict.size != lz_options.dict_size) {
-		lzma_free(next->coder->dict.buf, allocator);
-		next->coder->dict.buf
+	if (coder->dict.size != lz_options.dict_size) {
+		lzma_free(coder->dict.buf, allocator);
+		coder->dict.buf
 				= lzma_alloc(lz_options.dict_size, allocator);
-		if (next->coder->dict.buf == NULL)
+		if (coder->dict.buf == NULL)
 			return LZMA_MEM_ERROR;
 
-		next->coder->dict.size = lz_options.dict_size;
+		coder->dict.size = lz_options.dict_size;
 	}
 
 	lz_decoder_reset(next->coder);
@@ -268,21 +274,20 @@ lzma_lz_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		const size_t copy_size = my_min(lz_options.preset_dict_size,
 				lz_options.dict_size);
 		const size_t offset = lz_options.preset_dict_size - copy_size;
-		memcpy(next->coder->dict.buf, lz_options.preset_dict + offset,
+		memcpy(coder->dict.buf, lz_options.preset_dict + offset,
 				copy_size);
-		next->coder->dict.pos = copy_size;
-		next->coder->dict.full = copy_size;
+		coder->dict.pos = copy_size;
+		coder->dict.full = copy_size;
 	}
 
 	// Miscellaneous initializations
-	next->coder->next_finished = false;
-	next->coder->this_finished = false;
-	next->coder->temp.pos = 0;
-	next->coder->temp.size = 0;
+	coder->next_finished = false;
+	coder->this_finished = false;
+	coder->temp.pos = 0;
+	coder->temp.size = 0;
 
 	// Initialize the next filter in the chain, if any.
-	return lzma_next_filter_init(&next->coder->next, allocator,
-			filters + 1);
+	return lzma_next_filter_init(&coder->next, allocator, filters + 1);
 }
 
 
@@ -294,7 +299,8 @@ lzma_lz_decoder_memusage(size_t dictionary_size)
 
 
 extern void
-lzma_lz_decoder_uncompressed(lzma_coder *coder, lzma_vli uncompressed_size)
+lzma_lz_decoder_uncompressed(void *coder_ptr, lzma_vli uncompressed_size)
 {
+	lzma_coder *coder = coder_ptr;
 	coder->lz.set_uncompressed(coder->lz.coder, uncompressed_size);
 }
diff --git a/src/liblzma/lz/lz_decoder.h b/src/liblzma/lz/lz_decoder.h
index 277900af..754ccf37 100644
--- a/src/liblzma/lz/lz_decoder.h
+++ b/src/liblzma/lz/lz_decoder.h
@@ -53,21 +53,20 @@ typedef struct {
 
 typedef struct {
 	/// Data specific to the LZ-based decoder
-	lzma_coder *coder;
+	void *coder;
 
 	/// Function to decode from in[] to *dict
-	lzma_ret (*code)(lzma_coder *restrict coder,
+	lzma_ret (*code)(void *coder,
 			lzma_dict *restrict dict, const uint8_t *restrict in,
 			size_t *restrict in_pos, size_t in_size);
 
-	void (*reset)(lzma_coder *coder, const void *options);
+	void (*reset)(void *coder, const void *options);
 
 	/// Set the uncompressed size
-	void (*set_uncompressed)(lzma_coder *coder,
-			lzma_vli uncompressed_size);
+	void (*set_uncompressed)(void *coder, lzma_vli uncompressed_size);
 
 	/// Free allocated resources
-	void (*end)(lzma_coder *coder, const lzma_allocator *allocator);
+	void (*end)(void *coder, const lzma_allocator *allocator);
 
 } lzma_lz_decoder;
 
@@ -92,7 +91,7 @@ extern lzma_ret lzma_lz_decoder_init(lzma_next_coder *next,
 extern uint64_t lzma_lz_decoder_memusage(size_t dictionary_size);
 
 extern void lzma_lz_decoder_uncompressed(
-		lzma_coder *coder, lzma_vli uncompressed_size);
+		void *coder, lzma_vli uncompressed_size);
 
 
 //////////////////////
diff --git a/src/liblzma/lz/lz_encoder.c b/src/liblzma/lz/lz_encoder.c
index 5a2be798..9a74b7c4 100644
--- a/src/liblzma/lz/lz_encoder.c
+++ b/src/liblzma/lz/lz_encoder.c
@@ -23,7 +23,7 @@
 #include "memcmplen.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	/// LZ-based encoder e.g. LZMA
 	lzma_lz_encoder lz;
 
@@ -32,7 +32,7 @@ struct lzma_coder_s {
 
 	/// Next coder in the chain
 	lzma_next_coder next;
-};
+} lzma_coder;
 
 
 /// \brief      Moves the data in the input window to free space for new data
@@ -157,12 +157,14 @@ fill_window(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static lzma_ret
-lz_encode(lzma_coder *coder, const lzma_allocator *allocator,
+lz_encode(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size,
 		uint8_t *restrict out, size_t *restrict out_pos,
 		size_t out_size, lzma_action action)
 {
+	lzma_coder *coder = coder_ptr;
+
 	while (*out_pos < out_size
 			&& (*in_pos < in_size || action != LZMA_RUN)) {
 		// Read more data to coder->mf.buffer if needed.
@@ -481,8 +483,10 @@ lzma_lz_encoder_memusage(const lzma_lz_options *lz_options)
 
 
 static void
-lz_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+lz_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_coder *coder = coder_ptr;
+
 	lzma_next_end(&coder->next, allocator);
 
 	lzma_free(coder->mf.son, allocator);
@@ -500,10 +504,12 @@ lz_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-lz_encoder_update(lzma_coder *coder, const lzma_allocator *allocator,
+lz_encoder_update(void *coder_ptr, const lzma_allocator *allocator,
 		const lzma_filter *filters_null lzma_attribute((__unused__)),
 		const lzma_filter *reversed_filters)
 {
+	lzma_coder *coder = coder_ptr;
+
 	if (coder->lz.options_update == NULL)
 		return LZMA_PROG_ERROR;
 
@@ -528,50 +534,51 @@ lzma_lz_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 #endif
 
 	// Allocate and initialize the base data structure.
-	if (next->coder == NULL) {
-		next->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (next->coder == NULL)
+	lzma_coder *coder = next->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &lz_encode;
 		next->end = &lz_encoder_end;
 		next->update = &lz_encoder_update;
 
-		next->coder->lz.coder = NULL;
-		next->coder->lz.code = NULL;
-		next->coder->lz.end = NULL;
+		coder->lz.coder = NULL;
+		coder->lz.code = NULL;
+		coder->lz.end = NULL;
 
 		// mf.size is initialized to silence Valgrind
 		// when used on optimized binaries (GCC may reorder
 		// code in a way that Valgrind gets unhappy).
-		next->coder->mf.buffer = NULL;
-		next->coder->mf.size = 0;
-		next->coder->mf.hash = NULL;
-		next->coder->mf.son = NULL;
-		next->coder->mf.hash_count = 0;
-		next->coder->mf.sons_count = 0;
+		coder->mf.buffer = NULL;
+		coder->mf.size = 0;
+		coder->mf.hash = NULL;
+		coder->mf.son = NULL;
+		coder->mf.hash_count = 0;
+		coder->mf.sons_count = 0;
 
-		next->coder->next = LZMA_NEXT_CODER_INIT;
+		coder->next = LZMA_NEXT_CODER_INIT;
 	}
 
 	// Initialize the LZ-based encoder.
 	lzma_lz_options lz_options;
-	return_if_error(lz_init(&next->coder->lz, allocator,
+	return_if_error(lz_init(&coder->lz, allocator,
 			filters[0].options, &lz_options));
 
-	// Setup the size information into next->coder->mf and deallocate
+	// Setup the size information into coder->mf and deallocate
 	// old buffers if they have wrong size.
-	if (lz_encoder_prepare(&next->coder->mf, allocator, &lz_options))
+	if (lz_encoder_prepare(&coder->mf, allocator, &lz_options))
 		return LZMA_OPTIONS_ERROR;
 
 	// Allocate new buffers if needed, and do the rest of
 	// the initialization.
-	if (lz_encoder_init(&next->coder->mf, allocator, &lz_options))
+	if (lz_encoder_init(&coder->mf, allocator, &lz_options))
 		return LZMA_MEM_ERROR;
 
 	// Initialize the next filter in the chain, if any.
-	return lzma_next_filter_init(&next->coder->next, allocator,
-			filters + 1);
+	return lzma_next_filter_init(&coder->next, allocator, filters + 1);
 }
 
 
diff --git a/src/liblzma/lz/lz_encoder.h b/src/liblzma/lz/lz_encoder.h
index dad9c6b2..426dcd8a 100644
--- a/src/liblzma/lz/lz_encoder.h
+++ b/src/liblzma/lz/lz_encoder.h
@@ -191,19 +191,18 @@ typedef struct {
 
 typedef struct {
 	/// Data specific to the LZ-based encoder
-	lzma_coder *coder;
+	void *coder;
 
 	/// Function to encode from *dict to out[]
-	lzma_ret (*code)(lzma_coder *restrict coder,
+	lzma_ret (*code)(void *coder,
 			lzma_mf *restrict mf, uint8_t *restrict out,
 			size_t *restrict out_pos, size_t out_size);
 
 	/// Free allocated resources
-	void (*end)(lzma_coder *coder, const lzma_allocator *allocator);
+	void (*end)(void *coder, const lzma_allocator *allocator);
 
 	/// Update the options in the middle of the encoding.
-	lzma_ret (*options_update)(lzma_coder *coder,
-			const lzma_filter *filter);
+	lzma_ret (*options_update)(void *coder, const lzma_filter *filter);
 
 } lzma_lz_encoder;
 
diff --git a/src/liblzma/lzma/lzma2_decoder.c b/src/liblzma/lzma/lzma2_decoder.c
index 84982d2c..878c870a 100644
--- a/src/liblzma/lzma/lzma2_decoder.c
+++ b/src/liblzma/lzma/lzma2_decoder.c
@@ -16,7 +16,7 @@
 #include "lzma_decoder.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	enum sequence {
 		SEQ_CONTROL,
 		SEQ_UNCOMPRESSED_1,
@@ -50,14 +50,16 @@ struct lzma_coder_s {
 	bool need_dictionary_reset;
 
 	lzma_options_lzma options;
-};
+} lzma_lzma2_coder;
 
 
 static lzma_ret
-lzma2_decode(lzma_coder *restrict coder, lzma_dict *restrict dict,
+lzma2_decode(void *coder_ptr, lzma_dict *restrict dict,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size)
 {
+	lzma_lzma2_coder *restrict coder = coder_ptr;
+
 	// With SEQ_LZMA it is possible that no new input is needed to do
 	// some progress. The rest of the sequences assume that there is
 	// at least one byte of input.
@@ -209,8 +211,10 @@ lzma2_decode(lzma_coder *restrict coder, lzma_dict *restrict dict,
 
 
 static void
-lzma2_decoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+lzma2_decoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_lzma2_coder *coder = coder_ptr;
+
 	assert(coder->lzma.end == NULL);
 	lzma_free(coder->lzma.coder, allocator);
 
@@ -224,25 +228,27 @@ static lzma_ret
 lzma2_decoder_init(lzma_lz_decoder *lz, const lzma_allocator *allocator,
 		const void *opt, lzma_lz_options *lz_options)
 {
-	if (lz->coder == NULL) {
-		lz->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (lz->coder == NULL)
+	lzma_lzma2_coder *coder = lz->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_lzma2_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		lz->coder = coder;
 		lz->code = &lzma2_decode;
 		lz->end = &lzma2_decoder_end;
 
-		lz->coder->lzma = LZMA_LZ_DECODER_INIT;
+		coder->lzma = LZMA_LZ_DECODER_INIT;
 	}
 
 	const lzma_options_lzma *options = opt;
 
-	lz->coder->sequence = SEQ_CONTROL;
-	lz->coder->need_properties = true;
-	lz->coder->need_dictionary_reset = options->preset_dict == NULL
+	coder->sequence = SEQ_CONTROL;
+	coder->need_properties = true;
+	coder->need_dictionary_reset = options->preset_dict == NULL
 			|| options->preset_dict_size == 0;
 
-	return lzma_lzma_decoder_create(&lz->coder->lzma,
+	return lzma_lzma_decoder_create(&coder->lzma,
 			allocator, options, lz_options);
 }
 
@@ -263,7 +269,7 @@ lzma_lzma2_decoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 extern uint64_t
 lzma_lzma2_decoder_memusage(const void *options)
 {
-	return sizeof(lzma_coder)
+	return sizeof(lzma_lzma2_coder)
 			+ lzma_lzma_decoder_memusage_nocheck(options);
 }
 
diff --git a/src/liblzma/lzma/lzma2_encoder.c b/src/liblzma/lzma/lzma2_encoder.c
index b6756bfc..63588ee3 100644
--- a/src/liblzma/lzma/lzma2_encoder.c
+++ b/src/liblzma/lzma/lzma2_encoder.c
@@ -17,7 +17,7 @@
 #include "lzma2_encoder.h"
 
 
-struct lzma_coder_s {
+typedef struct {
 	enum {
 		SEQ_INIT,
 		SEQ_LZMA_ENCODE,
@@ -27,7 +27,7 @@ struct lzma_coder_s {
 	} sequence;
 
 	/// LZMA encoder
-	lzma_coder *lzma;
+	void *lzma;
 
 	/// LZMA options currently in use.
 	lzma_options_lzma opt_cur;
@@ -48,11 +48,11 @@ struct lzma_coder_s {
 
 	/// Buffer to hold the chunk header and LZMA compressed data
 	uint8_t buf[LZMA2_HEADER_MAX + LZMA2_CHUNK_MAX];
-};
+} lzma_lzma2_coder;
 
 
 static void
-lzma2_header_lzma(lzma_coder *coder)
+lzma2_header_lzma(lzma_lzma2_coder *coder)
 {
 	assert(coder->uncompressed_size > 0);
 	assert(coder->uncompressed_size <= LZMA2_UNCOMPRESSED_MAX);
@@ -108,7 +108,7 @@ lzma2_header_lzma(lzma_coder *coder)
 
 
 static void
-lzma2_header_uncompressed(lzma_coder *coder)
+lzma2_header_uncompressed(lzma_lzma2_coder *coder)
 {
 	assert(coder->uncompressed_size > 0);
 	assert(coder->uncompressed_size <= LZMA2_CHUNK_MAX);
@@ -133,10 +133,12 @@ lzma2_header_uncompressed(lzma_coder *coder)
 
 
 static lzma_ret
-lzma2_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
+lzma2_encode(void *coder_ptr, lzma_mf *restrict mf,
 		uint8_t *restrict out, size_t *restrict out_pos,
 		size_t out_size)
 {
+	lzma_lzma2_coder *restrict coder = coder_ptr;
+
 	while (*out_pos < out_size)
 	switch (coder->sequence) {
 	case SEQ_INIT:
@@ -262,8 +264,9 @@ lzma2_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
 
 
 static void
-lzma2_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
+lzma2_encoder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_lzma2_coder *coder = coder_ptr;
 	lzma_free(coder->lzma, allocator);
 	lzma_free(coder, allocator);
 	return;
@@ -271,8 +274,10 @@ lzma2_encoder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-lzma2_encoder_options_update(lzma_coder *coder, const lzma_filter *filter)
+lzma2_encoder_options_update(void *coder_ptr, const lzma_filter *filter)
 {
+	lzma_lzma2_coder *coder = coder_ptr;
+
 	// New options can be set only when there is no incomplete chunk.
 	// This is the case at the beginning of the raw stream and right
 	// after LZMA_SYNC_FLUSH.
@@ -310,30 +315,32 @@ lzma2_encoder_init(lzma_lz_encoder *lz, const lzma_allocator *allocator,
 	if (options == NULL)
 		return LZMA_PROG_ERROR;
 
-	if (lz->coder == NULL) {
-		lz->coder = lzma_alloc(sizeof(lzma_coder), allocator);
-		if (lz->coder == NULL)
+	lzma_lzma2_coder *coder = lz->coder;
+	if (coder == NULL) {
+		coder = lzma_alloc(sizeof(lzma_lzma2_coder), allocator);
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		lz->coder = coder;
 		lz->code = &lzma2_encode;
 		lz->end = &lzma2_encoder_end;
 		lz->options_update = &lzma2_encoder_options_update;
 
-		lz->coder->lzma = NULL;
+		coder->lzma = NULL;
 	}
 
-	lz->coder->opt_cur = *(const lzma_options_lzma *)(options);
+	coder->opt_cur = *(const lzma_options_lzma *)(options);
 
-	lz->coder->sequence = SEQ_INIT;
-	lz->coder->need_properties = true;
-	lz->coder->need_state_reset = false;
-	lz->coder->need_dictionary_reset
-			= lz->coder->opt_cur.preset_dict == NULL
-			|| lz->coder->opt_cur.preset_dict_size == 0;
+	coder->sequence = SEQ_INIT;
+	coder->need_properties = true;
+	coder->need_state_reset = false;
+	coder->need_dictionary_reset
+			= coder->opt_cur.preset_dict == NULL
+			|| coder->opt_cur.preset_dict_size == 0;
 
 	// Initialize LZMA encoder
-	return_if_error(lzma_lzma_encoder_create(&lz->coder->lzma, allocator,
-			&lz->coder->opt_cur, lz_options));
+	return_if_error(lzma_lzma_encoder_create(&coder->lzma, allocator,
+			&coder->opt_cur, lz_options));
 
 	// Make sure that we will always have enough history available in
 	// case we need to use uncompressed chunks. They are used when the
@@ -364,7 +371,7 @@ lzma_lzma2_encoder_memusage(const void *options)
 	if (lzma_mem == UINT64_MAX)
 		return UINT64_MAX;
 
-	return sizeof(lzma_coder) + lzma_mem;
+	return sizeof(lzma_lzma2_coder) + lzma_mem;
 }
 
 
diff --git a/src/liblzma/lzma/lzma_decoder.c b/src/liblzma/lzma/lzma_decoder.c
index b8f93170..eedc0733 100644
--- a/src/liblzma/lzma/lzma_decoder.c
+++ b/src/liblzma/lzma/lzma_decoder.c
@@ -161,7 +161,7 @@ typedef struct {
 } lzma_length_decoder;
 
 
-struct lzma_coder_s {
+typedef struct {
 	///////////////////
 	// Probabilities //
 	///////////////////
@@ -277,14 +277,16 @@ struct lzma_coder_s {
 	/// If decoding a literal: match byte.
 	/// If decoding a match: length of the match.
 	uint32_t len;
-};
+} lzma_lzma1_decoder;
 
 
 static lzma_ret
-lzma_decode(lzma_coder *restrict coder, lzma_dict *restrict dictptr,
+lzma_decode(void *coder_ptr, lzma_dict *restrict dictptr,
 		const uint8_t *restrict in,
 		size_t *restrict in_pos, size_t in_size)
 {
+	lzma_lzma1_decoder *restrict coder = coder_ptr;
+
 	////////////////////
 	// Initialization //
 	////////////////////
@@ -840,23 +842,17 @@ out:
 
 
 static void
-lzma_decoder_uncompressed(lzma_coder *coder, lzma_vli uncompressed_size)
+lzma_decoder_uncompressed(void *coder_ptr, lzma_vli uncompressed_size)
 {
+	lzma_lzma1_decoder *coder = coder_ptr;
 	coder->uncompressed_size = uncompressed_size;
 }
 
-/*
-extern void
-lzma_lzma_decoder_uncompressed(void *coder_ptr, lzma_vli uncompressed_size)
-{
-	// This is hack.
-	(*(lzma_coder **)(coder))->uncompressed_size = uncompressed_size;
-}
-*/
 
 static void
-lzma_decoder_reset(lzma_coder *coder, const void *opt)
+lzma_decoder_reset(void *coder_ptr, const void *opt)
 {
+	lzma_lzma1_decoder *coder = coder_ptr;
 	const lzma_options_lzma *options = opt;
 
 	// NOTE: We assume that lc/lp/pb are valid since they were
@@ -941,7 +937,7 @@ lzma_lzma_decoder_create(lzma_lz_decoder *lz, const lzma_allocator *allocator,
 		const void *opt, lzma_lz_options *lz_options)
 {
 	if (lz->coder == NULL) {
-		lz->coder = lzma_alloc(sizeof(lzma_coder), allocator);
+		lz->coder = lzma_alloc(sizeof(lzma_lzma1_decoder), allocator);
 		if (lz->coder == NULL)
 			return LZMA_MEM_ERROR;
 
@@ -1014,7 +1010,8 @@ extern uint64_t
 lzma_lzma_decoder_memusage_nocheck(const void *options)
 {
 	const lzma_options_lzma *const opt = options;
-	return sizeof(lzma_coder) + lzma_lz_decoder_memusage(opt->dict_size);
+	return sizeof(lzma_lzma1_decoder)
+			+ lzma_lz_decoder_memusage(opt->dict_size);
 }
 
 
diff --git a/src/liblzma/lzma/lzma_encoder.c b/src/liblzma/lzma/lzma_encoder.c
index 4c5f99c3..ba9ce698 100644
--- a/src/liblzma/lzma/lzma_encoder.c
+++ b/src/liblzma/lzma/lzma_encoder.c
@@ -43,7 +43,7 @@ literal_matched(lzma_range_encoder *rc, probability *subcoder,
 
 
 static inline void
-literal(lzma_coder *coder, lzma_mf *mf, uint32_t position)
+literal(lzma_lzma1_encoder *coder, lzma_mf *mf, uint32_t position)
 {
 	// Locate the literal byte to be encoded and the subcoder.
 	const uint8_t cur_byte = mf->buffer[
@@ -140,7 +140,7 @@ length(lzma_range_encoder *rc, lzma_length_encoder *lc,
 ///////////
 
 static inline void
-match(lzma_coder *coder, const uint32_t pos_state,
+match(lzma_lzma1_encoder *coder, const uint32_t pos_state,
 		const uint32_t distance, const uint32_t len)
 {
 	update_match(coder->state);
@@ -187,7 +187,7 @@ match(lzma_coder *coder, const uint32_t pos_state,
 ////////////////////
 
 static inline void
-rep_match(lzma_coder *coder, const uint32_t pos_state,
+rep_match(lzma_lzma1_encoder *coder, const uint32_t pos_state,
 		const uint32_t rep, const uint32_t len)
 {
 	if (rep == 0) {
@@ -231,7 +231,7 @@ rep_match(lzma_coder *coder, const uint32_t pos_state,
 //////////
 
 static void
-encode_symbol(lzma_coder *coder, lzma_mf *mf,
+encode_symbol(lzma_lzma1_encoder *coder, lzma_mf *mf,
 		uint32_t back, uint32_t len, uint32_t position)
 {
 	const uint32_t pos_state = position & coder->pos_mask;
@@ -265,7 +265,7 @@ encode_symbol(lzma_coder *coder, lzma_mf *mf,
 
 
 static bool
-encode_init(lzma_coder *coder, lzma_mf *mf)
+encode_init(lzma_lzma1_encoder *coder, lzma_mf *mf)
 {
 	assert(mf_position(mf) == 0);
 
@@ -293,7 +293,7 @@ encode_init(lzma_coder *coder, lzma_mf *mf)
 
 
 static void
-encode_eopm(lzma_coder *coder, uint32_t position)
+encode_eopm(lzma_lzma1_encoder *coder, uint32_t position)
 {
 	const uint32_t pos_state = position & coder->pos_mask;
 	rc_bit(&coder->rc, &coder->is_match[coder->state][pos_state], 1);
@@ -309,7 +309,7 @@ encode_eopm(lzma_coder *coder, uint32_t position)
 
 
 extern lzma_ret
-lzma_lzma_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
+lzma_lzma_encode(lzma_lzma1_encoder *restrict coder, lzma_mf *restrict mf,
 		uint8_t *restrict out, size_t *restrict out_pos,
 		size_t out_size, uint32_t limit)
 {
@@ -402,7 +402,7 @@ lzma_lzma_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
 
 
 static lzma_ret
-lzma_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
+lzma_encode(void *coder, lzma_mf *restrict mf,
 		uint8_t *restrict out, size_t *restrict out_pos,
 		size_t out_size)
 {
@@ -473,7 +473,8 @@ length_encoder_reset(lzma_length_encoder *lencoder,
 
 
 extern lzma_ret
-lzma_lzma_encoder_reset(lzma_coder *coder, const lzma_options_lzma *options)
+lzma_lzma_encoder_reset(lzma_lzma1_encoder *coder,
+		const lzma_options_lzma *options)
 {
 	if (!is_options_valid(options))
 		return LZMA_OPTIONS_ERROR;
@@ -545,18 +546,18 @@ lzma_lzma_encoder_reset(lzma_coder *coder, const lzma_options_lzma *options)
 
 
 extern lzma_ret
-lzma_lzma_encoder_create(lzma_coder **coder_ptr,
+lzma_lzma_encoder_create(void **coder_ptr,
 		const lzma_allocator *allocator,
 		const lzma_options_lzma *options, lzma_lz_options *lz_options)
 {
-	// Allocate lzma_coder if it wasn't already allocated.
+	// Allocate lzma_lzma1_encoder if it wasn't already allocated.
 	if (*coder_ptr == NULL) {
-		*coder_ptr = lzma_alloc(sizeof(lzma_coder), allocator);
+		*coder_ptr = lzma_alloc(sizeof(lzma_lzma1_encoder), allocator);
 		if (*coder_ptr == NULL)
 			return LZMA_MEM_ERROR;
 	}
 
-	lzma_coder *coder = *coder_ptr;
+	lzma_lzma1_encoder *coder = *coder_ptr;
 
 	// Set compression mode. We haven't validates the options yet,
 	// but it's OK here, since nothing bad happens with invalid
@@ -636,7 +637,7 @@ lzma_lzma_encoder_memusage(const void *options)
 	if (lz_memusage == UINT64_MAX)
 		return UINT64_MAX;
 
-	return (uint64_t)(sizeof(lzma_coder)) + lz_memusage;
+	return (uint64_t)(sizeof(lzma_lzma1_encoder)) + lz_memusage;
 }
 
 
diff --git a/src/liblzma/lzma/lzma_encoder.h b/src/liblzma/lzma/lzma_encoder.h
index cc9cc2f2..6cfdf228 100644
--- a/src/liblzma/lzma/lzma_encoder.h
+++ b/src/liblzma/lzma/lzma_encoder.h
@@ -17,6 +17,9 @@
 #include "common.h"
 
 
+typedef struct lzma_lzma1_encoder_s lzma_lzma1_encoder;
+
+
 extern lzma_ret lzma_lzma_encoder_init(lzma_next_coder *next,
 		const lzma_allocator *allocator,
 		const lzma_filter_info *filters);
@@ -36,16 +39,16 @@ extern bool lzma_lzma_lclppb_encode(
 
 /// Initializes raw LZMA encoder; this is used by LZMA2.
 extern lzma_ret lzma_lzma_encoder_create(
-		lzma_coder **coder_ptr, const lzma_allocator *allocator,
+		void **coder_ptr, const lzma_allocator *allocator,
 		const lzma_options_lzma *options, lzma_lz_options *lz_options);
 
 
 /// Resets an already initialized LZMA encoder; this is used by LZMA2.
 extern lzma_ret lzma_lzma_encoder_reset(
-		lzma_coder *coder, const lzma_options_lzma *options);
+		lzma_lzma1_encoder *coder, const lzma_options_lzma *options);
 
 
-extern lzma_ret lzma_lzma_encode(lzma_coder *restrict coder,
+extern lzma_ret lzma_lzma_encode(lzma_lzma1_encoder *restrict coder,
 		lzma_mf *restrict mf, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size,
 		uint32_t read_limit);
diff --git a/src/liblzma/lzma/lzma_encoder_optimum_fast.c b/src/liblzma/lzma/lzma_encoder_optimum_fast.c
index 9b30347c..6c53d2bd 100644
--- a/src/liblzma/lzma/lzma_encoder_optimum_fast.c
+++ b/src/liblzma/lzma/lzma_encoder_optimum_fast.c
@@ -18,7 +18,8 @@
 
 
 extern void
-lzma_lzma_optimum_fast(lzma_coder *restrict coder, lzma_mf *restrict mf,
+lzma_lzma_optimum_fast(lzma_lzma1_encoder *restrict coder,
+		lzma_mf *restrict mf,
 		uint32_t *restrict back_res, uint32_t *restrict len_res)
 {
 	const uint32_t nice_len = mf->nice_len;
diff --git a/src/liblzma/lzma/lzma_encoder_optimum_normal.c b/src/liblzma/lzma/lzma_encoder_optimum_normal.c
index a3605798..59f77343 100644
--- a/src/liblzma/lzma/lzma_encoder_optimum_normal.c
+++ b/src/liblzma/lzma/lzma_encoder_optimum_normal.c
@@ -19,7 +19,7 @@
 ////////////
 
 static uint32_t
-get_literal_price(const lzma_coder *const coder, const uint32_t pos,
+get_literal_price(const lzma_lzma1_encoder *const coder, const uint32_t pos,
 		const uint32_t prev_byte, const bool match_mode,
 		uint32_t match_byte, uint32_t symbol)
 {
@@ -65,7 +65,7 @@ get_len_price(const lzma_length_encoder *const lencoder,
 
 
 static inline uint32_t
-get_short_rep_price(const lzma_coder *const coder,
+get_short_rep_price(const lzma_lzma1_encoder *const coder,
 		const lzma_lzma_state state, const uint32_t pos_state)
 {
 	return rc_bit_0_price(coder->is_rep0[state])
@@ -74,7 +74,7 @@ get_short_rep_price(const lzma_coder *const coder,
 
 
 static inline uint32_t
-get_pure_rep_price(const lzma_coder *const coder, const uint32_t rep_index,
+get_pure_rep_price(const lzma_lzma1_encoder *const coder, const uint32_t rep_index,
 		const lzma_lzma_state state, uint32_t pos_state)
 {
 	uint32_t price;
@@ -99,7 +99,7 @@ get_pure_rep_price(const lzma_coder *const coder, const uint32_t rep_index,
 
 
 static inline uint32_t
-get_rep_price(const lzma_coder *const coder, const uint32_t rep_index,
+get_rep_price(const lzma_lzma1_encoder *const coder, const uint32_t rep_index,
 		const uint32_t len, const lzma_lzma_state state,
 		const uint32_t pos_state)
 {
@@ -109,7 +109,7 @@ get_rep_price(const lzma_coder *const coder, const uint32_t rep_index,
 
 
 static inline uint32_t
-get_dist_len_price(const lzma_coder *const coder, const uint32_t dist,
+get_dist_len_price(const lzma_lzma1_encoder *const coder, const uint32_t dist,
 		const uint32_t len, const uint32_t pos_state)
 {
 	const uint32_t dist_state = get_dist_state(len);
@@ -130,7 +130,7 @@ get_dist_len_price(const lzma_coder *const coder, const uint32_t dist,
 
 
 static void
-fill_dist_prices(lzma_coder *coder)
+fill_dist_prices(lzma_lzma1_encoder *coder)
 {
 	for (uint32_t dist_state = 0; dist_state < DIST_STATES; ++dist_state) {
 
@@ -185,7 +185,7 @@ fill_dist_prices(lzma_coder *coder)
 
 
 static void
-fill_align_prices(lzma_coder *coder)
+fill_align_prices(lzma_lzma1_encoder *coder)
 {
 	for (uint32_t i = 0; i < ALIGN_SIZE; ++i)
 		coder->align_prices[i] = rc_bittree_reverse_price(
@@ -221,7 +221,7 @@ make_short_rep(lzma_optimal *optimal)
 
 
 static void
-backward(lzma_coder *restrict coder, uint32_t *restrict len_res,
+backward(lzma_lzma1_encoder *restrict coder, uint32_t *restrict len_res,
 		uint32_t *restrict back_res, uint32_t cur)
 {
 	coder->opts_end_index = cur;
@@ -269,7 +269,7 @@ backward(lzma_coder *restrict coder, uint32_t *restrict len_res,
 //////////
 
 static inline uint32_t
-helper1(lzma_coder *restrict coder, lzma_mf *restrict mf,
+helper1(lzma_lzma1_encoder *restrict coder, lzma_mf *restrict mf,
 		uint32_t *restrict back_res, uint32_t *restrict len_res,
 		uint32_t position)
 {
@@ -441,7 +441,7 @@ helper1(lzma_coder *restrict coder, lzma_mf *restrict mf,
 
 
 static inline uint32_t
-helper2(lzma_coder *coder, uint32_t *reps, const uint8_t *buf,
+helper2(lzma_lzma1_encoder *coder, uint32_t *reps, const uint8_t *buf,
 		uint32_t len_end, uint32_t position, const uint32_t cur,
 		const uint32_t nice_len, const uint32_t buf_avail_full)
 {
@@ -797,7 +797,8 @@ helper2(lzma_coder *coder, uint32_t *reps, const uint8_t *buf,
 
 
 extern void
-lzma_lzma_optimum_normal(lzma_coder *restrict coder, lzma_mf *restrict mf,
+lzma_lzma_optimum_normal(lzma_lzma1_encoder *restrict coder,
+		lzma_mf *restrict mf,
 		uint32_t *restrict back_res, uint32_t *restrict len_res,
 		uint32_t position)
 {
diff --git a/src/liblzma/lzma/lzma_encoder_private.h b/src/liblzma/lzma/lzma_encoder_private.h
index 2f62d6cb..a2da969f 100644
--- a/src/liblzma/lzma/lzma_encoder_private.h
+++ b/src/liblzma/lzma/lzma_encoder_private.h
@@ -69,7 +69,7 @@ typedef struct {
 } lzma_optimal;
 
 
-struct lzma_coder_s {
+struct lzma_lzma1_encoder_s {
 	/// Range encoder
 	lzma_range_encoder rc;
 
@@ -138,10 +138,10 @@ struct lzma_coder_s {
 
 
 extern void lzma_lzma_optimum_fast(
-		lzma_coder *restrict coder, lzma_mf *restrict mf,
+		lzma_lzma1_encoder *restrict coder, lzma_mf *restrict mf,
 		uint32_t *restrict back_res, uint32_t *restrict len_res);
 
-extern void lzma_lzma_optimum_normal(lzma_coder *restrict coder,
+extern void lzma_lzma_optimum_normal(lzma_lzma1_encoder *restrict coder,
 		lzma_mf *restrict mf, uint32_t *restrict back_res,
 		uint32_t *restrict len_res, uint32_t position);
 
diff --git a/src/liblzma/simple/arm.c b/src/liblzma/simple/arm.c
index 258d870f..181d0e3b 100644
--- a/src/liblzma/simple/arm.c
+++ b/src/liblzma/simple/arm.c
@@ -15,7 +15,7 @@
 
 
 static size_t
-arm_code(lzma_simple *simple lzma_attribute((__unused__)),
+arm_code(void *simple lzma_attribute((__unused__)),
 		uint32_t now_pos, bool is_encoder,
 		uint8_t *buffer, size_t size)
 {
diff --git a/src/liblzma/simple/armthumb.c b/src/liblzma/simple/armthumb.c
index 06c21e40..eab4862d 100644
--- a/src/liblzma/simple/armthumb.c
+++ b/src/liblzma/simple/armthumb.c
@@ -15,7 +15,7 @@
 
 
 static size_t
-armthumb_code(lzma_simple *simple lzma_attribute((__unused__)),
+armthumb_code(void *simple lzma_attribute((__unused__)),
 		uint32_t now_pos, bool is_encoder,
 		uint8_t *buffer, size_t size)
 {
diff --git a/src/liblzma/simple/ia64.c b/src/liblzma/simple/ia64.c
index ba7249c0..580529e8 100644
--- a/src/liblzma/simple/ia64.c
+++ b/src/liblzma/simple/ia64.c
@@ -15,7 +15,7 @@
 
 
 static size_t
-ia64_code(lzma_simple *simple lzma_attribute((__unused__)),
+ia64_code(void *simple lzma_attribute((__unused__)),
 		uint32_t now_pos, bool is_encoder,
 		uint8_t *buffer, size_t size)
 {
diff --git a/src/liblzma/simple/powerpc.c b/src/liblzma/simple/powerpc.c
index 46899196..54dfbf10 100644
--- a/src/liblzma/simple/powerpc.c
+++ b/src/liblzma/simple/powerpc.c
@@ -15,7 +15,7 @@
 
 
 static size_t
-powerpc_code(lzma_simple *simple lzma_attribute((__unused__)),
+powerpc_code(void *simple lzma_attribute((__unused__)),
 		uint32_t now_pos, bool is_encoder,
 		uint8_t *buffer, size_t size)
 {
diff --git a/src/liblzma/simple/simple_coder.c b/src/liblzma/simple/simple_coder.c
index dba5417b..13ebabc7 100644
--- a/src/liblzma/simple/simple_coder.c
+++ b/src/liblzma/simple/simple_coder.c
@@ -18,7 +18,7 @@
 
 /// Copied or encodes/decodes more data to out[].
 static lzma_ret
-copy_or_code(lzma_coder *coder, const lzma_allocator *allocator,
+copy_or_code(lzma_simple_coder *coder, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
@@ -55,7 +55,7 @@ copy_or_code(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static size_t
-call_filter(lzma_coder *coder, uint8_t *buffer, size_t size)
+call_filter(lzma_simple_coder *coder, uint8_t *buffer, size_t size)
 {
 	const size_t filtered = coder->filter(coder->simple,
 			coder->now_pos, coder->is_encoder,
@@ -66,11 +66,13 @@ call_filter(lzma_coder *coder, uint8_t *buffer, size_t size)
 
 
 static lzma_ret
-simple_code(lzma_coder *coder, const lzma_allocator *allocator,
+simple_code(void *coder_ptr, const lzma_allocator *allocator,
 		const uint8_t *restrict in, size_t *restrict in_pos,
 		size_t in_size, uint8_t *restrict out,
 		size_t *restrict out_pos, size_t out_size, lzma_action action)
 {
+	lzma_simple_coder *coder = coder_ptr;
+
 	// TODO: Add partial support for LZMA_SYNC_FLUSH. We can support it
 	// in cases when the filter is able to filter everything. With most
 	// simple filters it can be done at offset that is a multiple of 2,
@@ -198,8 +200,9 @@ simple_code(lzma_coder *coder, const lzma_allocator *allocator,
 
 
 static void
-simple_coder_end(lzma_coder *coder, const lzma_allocator *allocator)
+simple_coder_end(void *coder_ptr, const lzma_allocator *allocator)
 {
+	lzma_simple_coder *coder = coder_ptr;
 	lzma_next_end(&coder->next, allocator);
 	lzma_free(coder->simple, allocator);
 	lzma_free(coder, allocator);
@@ -208,10 +211,12 @@ simple_coder_end(lzma_coder *coder, const lzma_allocator *allocator)
 
 
 static lzma_ret
-simple_coder_update(lzma_coder *coder, const lzma_allocator *allocator,
+simple_coder_update(void *coder_ptr, const lzma_allocator *allocator,
 		const lzma_filter *filters_null lzma_attribute((__unused__)),
 		const lzma_filter *reversed_filters)
 {
+	lzma_simple_coder *coder = coder_ptr;
+
 	// No update support, just call the next filter in the chain.
 	return lzma_next_filter_update(
 			&coder->next, allocator, reversed_filters + 1);
@@ -221,57 +226,57 @@ simple_coder_update(lzma_coder *coder, const lzma_allocator *allocator,
 extern lzma_ret
 lzma_simple_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		const lzma_filter_info *filters,
-		size_t (*filter)(lzma_simple *simple, uint32_t now_pos,
+		size_t (*filter)(void *simple, uint32_t now_pos,
 			bool is_encoder, uint8_t *buffer, size_t size),
 		size_t simple_size, size_t unfiltered_max,
 		uint32_t alignment, bool is_encoder)
 {
-	// Allocate memory for the lzma_coder structure if needed.
-	if (next->coder == NULL) {
+	// Allocate memory for the lzma_simple_coder structure if needed.
+	lzma_simple_coder *coder = next->coder;
+	if (coder == NULL) {
 		// Here we allocate space also for the temporary buffer. We
 		// need twice the size of unfiltered_max, because then it
 		// is always possible to filter at least unfiltered_max bytes
 		// more data in coder->buffer[] if it can be filled completely.
-		next->coder = lzma_alloc(sizeof(lzma_coder)
+		coder = lzma_alloc(sizeof(lzma_simple_coder)
 				+ 2 * unfiltered_max, allocator);
-		if (next->coder == NULL)
+		if (coder == NULL)
 			return LZMA_MEM_ERROR;
 
+		next->coder = coder;
 		next->code = &simple_code;
 		next->end = &simple_coder_end;
 		next->update = &simple_coder_update;
 
-		next->coder->next = LZMA_NEXT_CODER_INIT;
-		next->coder->filter = filter;
-		next->coder->allocated = 2 * unfiltered_max;
+		coder->next = LZMA_NEXT_CODER_INIT;
+		coder->filter = filter;
+		coder->allocated = 2 * unfiltered_max;
 
 		// Allocate memory for filter-specific data structure.
 		if (simple_size > 0) {
-			next->coder->simple = lzma_alloc(
-					simple_size, allocator);
-			if (next->coder->simple == NULL)
+			coder->simple = lzma_alloc(simple_size, allocator);
+			if (coder->simple == NULL)
 				return LZMA_MEM_ERROR;
 		} else {
-			next->coder->simple = NULL;
+			coder->simple = NULL;
 		}
 	}
 
 	if (filters[0].options != NULL) {
 		const lzma_options_bcj *simple = filters[0].options;
-		next->coder->now_pos = simple->start_offset;
-		if (next->coder->now_pos & (alignment - 1))
+		coder->now_pos = simple->start_offset;
+		if (coder->now_pos & (alignment - 1))
 			return LZMA_OPTIONS_ERROR;
 	} else {
-		next->coder->now_pos = 0;
+		coder->now_pos = 0;
 	}
 
 	// Reset variables.
-	next->coder->is_encoder = is_encoder;
-	next->coder->end_was_reached = false;
-	next->coder->pos = 0;
-	next->coder->filtered = 0;
-	next->coder->size = 0;
+	coder->is_encoder = is_encoder;
+	coder->end_was_reached = false;
+	coder->pos = 0;
+	coder->filtered = 0;
+	coder->size = 0;
 
-	return lzma_next_filter_init(
-			&next->coder->next, allocator, filters + 1);
+	return lzma_next_filter_init(&coder->next, allocator, filters + 1);
 }
diff --git a/src/liblzma/simple/simple_private.h b/src/liblzma/simple/simple_private.h
index bb20cb41..9d2c0fdd 100644
--- a/src/liblzma/simple/simple_private.h
+++ b/src/liblzma/simple/simple_private.h
@@ -16,9 +16,7 @@
 #include "simple_coder.h"
 
 
-typedef struct lzma_simple_s lzma_simple;
-
-struct lzma_coder_s {
+typedef struct {
 	/// Next filter in the chain
 	lzma_next_coder next;
 
@@ -33,12 +31,12 @@ struct lzma_coder_s {
 
 	/// Pointer to filter-specific function, which does
 	/// the actual filtering.
-	size_t (*filter)(lzma_simple *simple, uint32_t now_pos,
+	size_t (*filter)(void *simple, uint32_t now_pos,
 			bool is_encoder, uint8_t *buffer, size_t size);
 
 	/// Pointer to filter-specific data, or NULL if filter doesn't need
 	/// any extra data.
-	lzma_simple *simple;
+	void *simple;
 
 	/// The lowest 32 bits of the current position in the data. Most
 	/// filters need this to do conversions between absolute and relative
@@ -62,13 +60,13 @@ struct lzma_coder_s {
 
 	/// Temporary buffer
 	uint8_t buffer[];
-};
+} lzma_simple_coder;
 
 
 extern lzma_ret lzma_simple_coder_init(lzma_next_coder *next,
 		const lzma_allocator *allocator,
 		const lzma_filter_info *filters,
-		size_t (*filter)(lzma_simple *simple, uint32_t now_pos,
+		size_t (*filter)(void *simple, uint32_t now_pos,
 			bool is_encoder, uint8_t *buffer, size_t size),
 		size_t simple_size, size_t unfiltered_max,
 		uint32_t alignment, bool is_encoder);
diff --git a/src/liblzma/simple/sparc.c b/src/liblzma/simple/sparc.c
index 53ee49d1..74b2655f 100644
--- a/src/liblzma/simple/sparc.c
+++ b/src/liblzma/simple/sparc.c
@@ -15,7 +15,7 @@
 
 
 static size_t
-sparc_code(lzma_simple *simple lzma_attribute((__unused__)),
+sparc_code(void *simple lzma_attribute((__unused__)),
 		uint32_t now_pos, bool is_encoder,
 		uint8_t *buffer, size_t size)
 {
diff --git a/src/liblzma/simple/x86.c b/src/liblzma/simple/x86.c
index 3b2b4f85..0b14807e 100644
--- a/src/liblzma/simple/x86.c
+++ b/src/liblzma/simple/x86.c
@@ -17,14 +17,14 @@
 #define Test86MSByte(b) ((b) == 0 || (b) == 0xFF)
 
 
-struct lzma_simple_s {
+typedef struct {
 	uint32_t prev_mask;
 	uint32_t prev_pos;
-};
+} lzma_simple_x86;
 
 
 static size_t
-x86_code(lzma_simple *simple, uint32_t now_pos, bool is_encoder,
+x86_code(void *simple_ptr, uint32_t now_pos, bool is_encoder,
 		uint8_t *buffer, size_t size)
 {
 	static const bool MASK_TO_ALLOWED_STATUS[8]
@@ -33,6 +33,7 @@ x86_code(lzma_simple *simple, uint32_t now_pos, bool is_encoder,
 	static const uint32_t MASK_TO_BIT_NUMBER[8]
 			= { 0, 1, 2, 2, 3, 3, 3, 3 };
 
+	lzma_simple_x86 *simple = simple_ptr;
 	uint32_t prev_mask = simple->prev_mask;
 	uint32_t prev_pos = simple->prev_pos;
 
@@ -127,11 +128,13 @@ x86_coder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 		const lzma_filter_info *filters, bool is_encoder)
 {
 	const lzma_ret ret = lzma_simple_coder_init(next, allocator, filters,
-			&x86_code, sizeof(lzma_simple), 5, 1, is_encoder);
+			&x86_code, sizeof(lzma_simple_x86), 5, 1, is_encoder);
 
 	if (ret == LZMA_OK) {
-		next->coder->simple->prev_mask = 0;
-		next->coder->simple->prev_pos = (uint32_t)(-5);
+		lzma_simple_coder *coder = next->coder;
+		lzma_simple_x86 *simple = coder->simple;
+		simple->prev_mask = 0;
+		simple->prev_pos = (uint32_t)(-5);
 	}
 
 	return ret;