diff --git a/crypto/bn/asm/x86_64-gcc.c b/crypto/bn/asm/x86_64-gcc.c
index b1b8a1109..2d80f192d 100644
--- a/crypto/bn/asm/x86_64-gcc.c
+++ b/crypto/bn/asm/x86_64-gcc.c
@@ -185,7 +185,7 @@ BN_ULONG bn_add_words (BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,int
 
 	if (n <= 0) return 0;
 
-	asm (
+	asm volatile (
 	"	subq	%2,%2		\n"
 	".align 16			\n"
 	"1:	movq	(%4,%2,8),%0	\n"
@@ -196,7 +196,7 @@ BN_ULONG bn_add_words (BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,int
 	"	sbbq	%0,%0		\n"
 		: "=&a"(ret),"+c"(n),"=&r"(i)
 		: "r"(rp),"r"(ap),"r"(bp)
-		: "cc"
+		: "cc", "memory"
 	);
 
   return ret&1;
@@ -208,7 +208,7 @@ BN_ULONG bn_sub_words (BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,int
 
 	if (n <= 0) return 0;
 
-	asm (
+	asm volatile (
 	"	subq	%2,%2		\n"
 	".align 16			\n"
 	"1:	movq	(%4,%2,8),%0	\n"
@@ -219,7 +219,7 @@ BN_ULONG bn_sub_words (BN_ULONG *rp, const BN_ULONG *ap, const BN_ULONG *bp,int
 	"	sbbq	%0,%0		\n"
 		: "=&a"(ret),"+c"(n),"=&r"(i)
 		: "r"(rp),"r"(ap),"r"(bp)
-		: "cc"
+		: "cc", "memory"
 	);
 
   return ret&1;