diff --git a/GNUmakefile b/GNUmakefile
index 7b45f5b4..bd6e90c3 100755
--- a/GNUmakefile
+++ b/GNUmakefile
@@ -394,6 +394,7 @@ ifeq ($(IS_NEON),1)
     SIMECK_FLAG = -march=armv7-a -mfloat-abi=$(FP_ABI) -mfpu=neon
     SIMON_FLAG = -march=armv7-a -mfloat-abi=$(FP_ABI) -mfpu=neon
     SPECK_FLAG = -march=armv7-a -mfloat-abi=$(FP_ABI) -mfpu=neon
+    SM4_FLAG = -march=armv7-a -mfloat-abi=$(FP_ABI) -mfpu=neon
   endif
 endif
 
@@ -408,6 +409,7 @@ ifeq ($(IS_ARMV8),1)
     SIMECK_FLAG = -march=armv8-a
     SIMON_FLAG = -march=armv8-a
     SPECK_FLAG = -march=armv8-a
+    SM4_FLAG = -march=armv8-a
   endif
   HAVE_CRC = $(shell echo | $(CXX) -x c++ $(CXXFLAGS) -march=armv8-a+crc -dM -E - 2>/dev/null | $(GREP) -i -c __ARM_FEATURE_CRC32)
   ifeq ($(HAVE_CRC),1)
@@ -419,6 +421,10 @@ ifeq ($(IS_ARMV8),1)
     GCM_FLAG = -march=armv8-a+crypto
     SHA_FLAG = -march=armv8-a+crypto
   endif
+  HAVE_CRYPTO = $(shell echo | $(CXX) -x c++ $(CXXFLAGS) -march=armv8.4-a+crypto -dM -E - 2>/dev/null | $(GREP) -i -c __ARM_FEATURE_CRYPTO)
+  ifeq ($(HAVE_CRYPTO),1)
+    SM4_FLAG = -march=armv8.4-a+crypto
+  endif
 endif
 
 # PowerPC and PowerPC-64
diff --git a/GNUmakefile-cross b/GNUmakefile-cross
index 48a364a2..7611d24d 100755
--- a/GNUmakefile-cross
+++ b/GNUmakefile-cross
@@ -276,6 +276,10 @@ ifneq ($(IS_ARMv8),0)
     GCM_FLAG = -march=armv8-a+crypto
     SHA_FLAG = -march=armv8-a+crypto
   endif
+  HAVE_CRYPTO := $(shell echo | $(CXX) -x c++ $(CXXFLAGS) -march=armv8.4-a+crypto -dM -E - 2>/dev/null | $(EGREP) -i -c __ARM_FEATURE_CRYPTO)
+  ifeq ($(HAVE_CRYPTO),1)
+    SM4_FLAG = -march=armv8.4-a+crypto
+  endif
 endif
 
 # i686 and x86_64
diff --git a/sm4-simd.cpp b/sm4-simd.cpp
index 7347962a..fca4a941 100644
--- a/sm4-simd.cpp
+++ b/sm4-simd.cpp
@@ -6,8 +6,9 @@
 //    source file is needed because additional CXXFLAGS are required to enable
 //    the appropriate instructions sets in some build configurations.
 //
-//    Based on Markku-Juhani O. Saarinen work at https://github.com/mjosaarinen/sm4ni.
+//    AES-NI based on Markku-Juhani O. Saarinen work at https://github.com/mjosaarinen/sm4ni.
 //
+//    ARMv8 is upcoming.
 
 #include "pch.h"
 #include "config.h"
@@ -25,7 +26,7 @@
 # include <wmmintrin.h>
 #endif
 
-#if (CRYPTOPP_ARM_NEON_AVAILABLE)
+#if (CRYPTOPP_ARM_NEON_AVAILABLE) && 0
 # include <arm_neon.h>
 #endif
 
@@ -329,7 +330,7 @@ size_t SM4_Enc_AdvancedProcessBlocks_AESNI(const word32* subKeys, size_t rounds,
 }
 #endif // CRYPTOPP_AESNI_AVAILABLE
 
-#if defined(CRYPTOPP_ARM_NEON_AVAILABLE)
+#if defined(CRYPTOPP_ARM_NEON_AVAILABLE) && 0
 size_t SM4_Enc_AdvancedProcessBlocks_NEON(const word32* subKeys, size_t rounds,
     const byte *inBlocks, const byte *xorBlocks, byte *outBlocks, size_t length, word32 flags)
 {