diff --git a/lib/x86/adler32_impl.h b/lib/x86/adler32_impl.h
index cc118c76..f1102b5e 100644
--- a/lib/x86/adler32_impl.h
+++ b/lib/x86/adler32_impl.h
@@ -72,6 +72,7 @@
 #endif
 
 #if (GCC_PREREQ(8, 1) || CLANG_PREREQ(6, 0, 10000000) || MSVC_PREREQ(1920)) && \
+	!(CLANG_PREREQ(18, 0, 18000000) && !CLANG_PREREQ(19, 0, 19000000)) && \
 	!defined(LIBDEFLATE_ASSEMBLER_DOES_NOT_SUPPORT_AVX512VNNI)
 /*
  * AVX512VNNI implementation using 256-bit vectors.  This is very similar to the
@@ -82,7 +83,7 @@
  */
 #  define adler32_x86_avx512_vl256_vnni	adler32_x86_avx512_vl256_vnni
 #  define SUFFIX				   _avx512_vl256_vnni
-#  define ATTRIBUTES		_target_attribute("avx512bw,avx512vl,avx512vnni" NO_EVEX512)
+#  define ATTRIBUTES		_target_attribute("avx512bw,avx512vl,avx512vnni")
 #  define VL			32
 #  define USE_VNNI		1
 #  define USE_AVX512		1
@@ -94,7 +95,7 @@
  */
 #  define adler32_x86_avx512_vl512_vnni	adler32_x86_avx512_vl512_vnni
 #  define SUFFIX				   _avx512_vl512_vnni
-#  define ATTRIBUTES		_target_attribute("avx512bw,avx512vnni" EVEX512)
+#  define ATTRIBUTES		_target_attribute("avx512bw,avx512vnni")
 #  define VL			64
 #  define USE_VNNI		1
 #  define USE_AVX512		1
diff --git a/lib/x86/cpu_features.h b/lib/x86/cpu_features.h
index 032896a7..cb225b98 100644
--- a/lib/x86/cpu_features.h
+++ b/lib/x86/cpu_features.h
@@ -165,15 +165,6 @@ static inline u32 get_x86_cpu_features(void) { return 0; }
 #  define HAVE_AVXVNNI(features)	((features) & X86_CPU_FEATURE_AVXVNNI)
 #endif
 
-#if ((CLANG_PREREQ(18, 0, 18000000) && !CLANG_PREREQ(19, 0, 19000000))) \
-	&& !defined(__EVEX512__) /* avoid subtracting the evex512 feature */
-#  define EVEX512	",evex512"	/* needed to override potential -mno-evex512 */
-#  define NO_EVEX512	",no-evex512"
-#else
-#  define EVEX512	""
-#  define NO_EVEX512	""
-#endif
-
 #endif /* ARCH_X86_32 || ARCH_X86_64 */
 
 #endif /* LIB_X86_CPU_FEATURES_H */
diff --git a/lib/x86/crc32_impl.h b/lib/x86/crc32_impl.h
index 47551c5f..4fbdef7e 100644
--- a/lib/x86/crc32_impl.h
+++ b/lib/x86/crc32_impl.h
@@ -92,6 +92,7 @@ static const u8 MAYBE_UNUSED shift_tab[48] = {
 #endif
 
 #if (GCC_PREREQ(10, 1) || CLANG_PREREQ(6, 0, 10000000) || MSVC_PREREQ(1920)) && \
+	!(CLANG_PREREQ(18, 0, 18000000) && !CLANG_PREREQ(19, 0, 19000000)) && \
 	!defined(LIBDEFLATE_ASSEMBLER_DOES_NOT_SUPPORT_VPCLMULQDQ)
 /*
  * VPCLMULQDQ/AVX512 implementation using 256-bit vectors.  This is very similar
@@ -104,7 +105,7 @@ static const u8 MAYBE_UNUSED shift_tab[48] = {
  */
 #  define crc32_x86_vpclmulqdq_avx512_vl256  crc32_x86_vpclmulqdq_avx512_vl256
 #  define SUFFIX				      _vpclmulqdq_avx512_vl256
-#  define ATTRIBUTES		_target_attribute("vpclmulqdq,pclmul,avx512bw,avx512vl" NO_EVEX512)
+#  define ATTRIBUTES		_target_attribute("vpclmulqdq,pclmul,avx512bw,avx512vl")
 #  define VL			32
 #  define USE_AVX512		1
 #  include "crc32_pclmul_template.h"
@@ -117,7 +118,7 @@ static const u8 MAYBE_UNUSED shift_tab[48] = {
  */
 #  define crc32_x86_vpclmulqdq_avx512_vl512  crc32_x86_vpclmulqdq_avx512_vl512
 #  define SUFFIX				      _vpclmulqdq_avx512_vl512
-#  define ATTRIBUTES		_target_attribute("vpclmulqdq,pclmul,avx512bw,avx512vl" EVEX512)
+#  define ATTRIBUTES		_target_attribute("vpclmulqdq,pclmul,avx512bw,avx512vl")
 #  define VL			64
 #  define USE_AVX512		1
 #  include "crc32_pclmul_template.h"