diff --git a/src/liblzma/check/crc32_fast.c b/src/liblzma/check/crc32_fast.c
index 0b667d8b..1fadb70f 100644
--- a/src/liblzma/check/crc32_fast.c
+++ b/src/liblzma/check/crc32_fast.c
@@ -128,7 +128,7 @@ typedef uint32_t (*crc32_func_type)(
 // Clang 16.0.0 and older has a bug where it marks the ifunc resolver
 // function as unused since it is static and never used outside of
 // __attribute__((__ifunc__())).
-#if defined(HAVE_FUNC_ATTRIBUTE_IFUNC) && defined(__clang__)
+#if defined(CRC_USE_IFUNC) && defined(__clang__)
 #	pragma GCC diagnostic push
 #	pragma GCC diagnostic ignored "-Wunused-function"
 #endif
@@ -143,11 +143,11 @@ crc32_resolve(void)
 			? &crc32_arch_optimized : &crc32_generic;
 }
 
-#if defined(HAVE_FUNC_ATTRIBUTE_IFUNC) && defined(__clang__)
+#if defined(CRC_USE_IFUNC) && defined(__clang__)
 #	pragma GCC diagnostic pop
 #endif
 
-#ifndef HAVE_FUNC_ATTRIBUTE_IFUNC
+#ifndef CRC_USE_IFUNC
 
 #ifdef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR
 // Constructor method.
diff --git a/src/liblzma/check/crc64_fast.c b/src/liblzma/check/crc64_fast.c
index d1ab6862..6a4e6d24 100644
--- a/src/liblzma/check/crc64_fast.c
+++ b/src/liblzma/check/crc64_fast.c
@@ -94,7 +94,7 @@ crc64_generic(const uint8_t *buf, size_t size, uint64_t crc)
 typedef uint64_t (*crc64_func_type)(
 		const uint8_t *buf, size_t size, uint64_t crc);
 
-#if defined(HAVE_FUNC_ATTRIBUTE_IFUNC) && defined(__clang__)
+#if defined(CRC_USE_IFUNC) && defined(__clang__)
 #	pragma GCC diagnostic push
 #	pragma GCC diagnostic ignored "-Wunused-function"
 #endif
@@ -106,11 +106,11 @@ crc64_resolve(void)
 			? &crc64_arch_optimized : &crc64_generic;
 }
 
-#if defined(HAVE_FUNC_ATTRIBUTE_IFUNC) && defined(__clang__)
+#if defined(CRC_USE_IFUNC) && defined(__clang__)
 #	pragma GCC diagnostic pop
 #endif
 
-#ifndef HAVE_FUNC_ATTRIBUTE_IFUNC
+#ifndef CRC_USE_IFUNC
 
 #ifdef HAVE_FUNC_ATTRIBUTE_CONSTRUCTOR
 #	define CRC64_SET_FUNC_ATTR __attribute__((__constructor__))