diff --git a/tests/test_block_header.c b/tests/test_block_header.c
index 747925b3..43c7df43 100644
--- a/tests/test_block_header.c
+++ b/tests/test_block_header.c
@@ -189,7 +189,7 @@ test_lzma_block_header_size(void)
 
 	// Use an invalid block option. The check type isn't stored in
 	// the Block Header and so _header_size ignores it.
-	block.check = 0x1000;
+	block.check = INVALID_LZMA_CHECK_ID;
 	block.ignore_check = false;
 
 	assert_lzma_ret(lzma_block_header_size(&block), LZMA_OK);
@@ -270,7 +270,7 @@ test_lzma_block_header_encode(void)
 	block.uncompressed_size = LZMA_VLI_UNKNOWN;
 
 	// Test invalid block check
-	block.check = 0x1000;
+	block.check = INVALID_LZMA_CHECK_ID;
 	block.ignore_check = false;
 	assert_lzma_ret(lzma_block_header_encode(&block, out),
 			LZMA_PROG_ERROR);
@@ -466,7 +466,7 @@ test_lzma_block_header_decode(void)
 	assert_uint_eq(decoded_block.version, 1);
 
 	// Test bad check type
-	decoded_block.check = LZMA_CHECK_ID_MAX + 1;
+	decoded_block.check = INVALID_LZMA_CHECK_ID;
 	assert_lzma_ret(lzma_block_header_decode(&decoded_block, NULL, out),
 			LZMA_PROG_ERROR);
 	decoded_block.check = LZMA_CHECK_CRC32;
diff --git a/tests/test_check.c b/tests/test_check.c
index 1d5b3a10..cb1ad251 100644
--- a/tests/test_check.c
+++ b/tests/test_check.c
@@ -176,7 +176,7 @@ test_lzma_check_size(void)
 	for (lzma_check i = 0; i < ARRAY_SIZE(expected_check_sizes); i++)
 		assert_uint_eq(expected_check_sizes[i], lzma_check_size(i));
 
-	assert_uint_eq(lzma_check_size(LZMA_CHECK_ID_MAX + 1), UINT32_MAX);
+	assert_uint_eq(lzma_check_size(INVALID_LZMA_CHECK_ID), UINT32_MAX);
 }
 
 
diff --git a/tests/test_stream_flags.c b/tests/test_stream_flags.c
index 26b4c613..2248e67a 100644
--- a/tests/test_stream_flags.c
+++ b/tests/test_stream_flags.c
@@ -87,7 +87,7 @@ test_lzma_stream_header_encode(void)
 	flags.version = 0;
 
 	// Should fail if Check ID is invalid
-	flags.check = LZMA_CHECK_ID_MAX + 1;
+	flags.check = INVALID_LZMA_CHECK_ID;
 	assert_lzma_ret(lzma_stream_header_encode(&flags, header),
 			LZMA_PROG_ERROR);
 	flags.check = LZMA_CHECK_CRC32;
@@ -170,7 +170,7 @@ test_lzma_stream_footer_encode(void)
 	flags.version = 0;
 
 	// Should fail if Check ID is invalid
-	flags.check = LZMA_CHECK_ID_MAX + 1;
+	flags.check = INVALID_LZMA_CHECK_ID;
 	assert_lzma_ret(lzma_stream_footer_encode(&flags, footer),
 			LZMA_PROG_ERROR);
 
@@ -410,10 +410,10 @@ test_lzma_stream_flags_compare(void)
 	second.version = 0;
 
 	// Check types must be under the maximum
-	first.check = LZMA_CHECK_ID_MAX + 1;
+	first.check = INVALID_LZMA_CHECK_ID;
 	assert_lzma_ret(lzma_stream_flags_compare(&first, &second),
 			LZMA_PROG_ERROR);
-	second.check = LZMA_CHECK_ID_MAX + 1;
+	second.check = INVALID_LZMA_CHECK_ID;
 	assert_lzma_ret(lzma_stream_flags_compare(&first, &second),
 			LZMA_PROG_ERROR);
 	first.check = LZMA_CHECK_CRC32;
diff --git a/tests/tests.h b/tests/tests.h
index 4d6169b0..8d53e9de 100644
--- a/tests/tests.h
+++ b/tests/tests.h
@@ -19,6 +19,15 @@
 #include "tuktest.h"
 
 
+// Invalid value for the lzma_check enumeration. This must be positive
+// but small enough to fit into signed char since the underlying type might
+// one some platform be a signed char.
+//
+// Don't put LZMA_ at the beginning of the name so that it is obvious that
+// this constant doesn't come from the API headers.
+#define INVALID_LZMA_CHECK_ID ((lzma_check)(LZMA_CHECK_ID_MAX + 1))
+
+
 #define memcrap(buf, size) memset(buf, 0xFD, size)