diff --git a/src/internal.c b/src/internal.c
index 6c5a70ecc9c..7897a294bfa 100644
--- a/src/internal.c
+++ b/src/internal.c
@@ -1169,7 +1169,7 @@ static int ImportKeyState(WOLFSSL* ssl, const byte* exp, word32 len, byte ver,
         XMEMCPY(keys->server_write_MAC_secret, exp + idx, sz); idx += sz;
     }
 #else
-    if (sz + idx > len) {
+    if ((sz * 2) + idx > len) {
         return BUFFER_E;
     }
     idx += sz; idx += sz;