diff --git a/wolfcrypt/src/sha512.c b/wolfcrypt/src/sha512.c
index 16e31f1a9..b96b29ad6 100644
--- a/wolfcrypt/src/sha512.c
+++ b/wolfcrypt/src/sha512.c
@@ -156,6 +156,17 @@
     /* #define DEBUG_YMM  */
 #endif
 
+#if defined(HAVE_BYTEREVERSE64) && \
+        !defined(HAVE_INTEL_AVX1) && !defined(HAVE_INTEL_AVX2)
+    #define ByteReverseWords64(out, in, size) ByteReverseWords64_1(out, size)
+    #define ByteReverseWords64_1(buf, size) \
+        { unsigned int i ;\
+            for(i=0; i< size/sizeof(word64); i++){\
+                __asm__ volatile("bswapq %0":"+r"(buf[i])::) ;\
+            }\
+        }
+#endif
+
 #if defined(WOLFSSL_IMX6_CAAM) && !defined(NO_IMX6_CAAM_HASH)
     /* functions defined in wolfcrypt/src/port/caam/caam_sha.c */
 #else