diff --git a/wolfcrypt/src/cmac.c b/wolfcrypt/src/cmac.c
index 49ab1657c2..460d02a078 100644
--- a/wolfcrypt/src/cmac.c
+++ b/wolfcrypt/src/cmac.c
@@ -211,7 +211,7 @@ int wc_CmacUpdate(Cmac* cmac, const byte* in, word32 inSz)
     /* Clear CRYPTOCB_UNAVAILABLE return code */
     ret = 0;
 
-    while (inSz != 0) {
+    while ((ret == 0) && (inSz != 0)) {
         word32 add = min(inSz, AES_BLOCK_SIZE - cmac->bufferSz);
         XMEMCPY(&cmac->buffer[cmac->bufferSz], in, add);