diff --git a/include/mbedtls/bn_mul.h b/include/mbedtls/bn_mul.h
index cac3f14577..7f8eb1a696 100644
--- a/include/mbedtls/bn_mul.h
+++ b/include/mbedtls/bn_mul.h
@@ -520,7 +520,7 @@
         "swi   r3,   %2         \n\t"   \
         : "=m" (c), "=m" (d), "=m" (s)              \
         : "m" (s), "m" (d), "m" (c), "m" (b)        \
-        : "r3", "r4"  "r5", "r6", "r7", "r8",       \
+        : "r3", "r4", "r5", "r6", "r7", "r8",       \
           "r9", "r10", "r11", "r12", "r13"          \
     );