diff --git a/include/mbedtls/bn_mul.h b/include/mbedtls/bn_mul.h
index e77103fea..951024595 100644
--- a/include/mbedtls/bn_mul.h
+++ b/include/mbedtls/bn_mul.h
@@ -46,8 +46,9 @@
 #define asm __asm
 #endif
 
-/* armcc5 --gnu defined __GNUC__ but doesn't support GNU's extended asm */
-#if defined(__GNUC__) && !defined(__ARMCC_VERSION)
+/* armcc5 --gnu defines __GNUC__ but doesn't support GNU's extended asm */
+#if defined(__GNUC__) && \
+    ( !defined(__ARMCC_VERSION) || __ARMCC_VERSION >= 6000000 )
 #if defined(__i386__)
 
 #define MULADDC_INIT                        \