diff --git a/cbits/md5.c b/cbits/md5.c
index 0570cbbd..c9283164 100644
--- a/cbits/md5.c
+++ b/cbits/md5.c
@@ -130,7 +130,7 @@ MD5Final(byte digest[16], struct MD5Context *ctx)
 
 	byteSwap(ctx->buf, 4);
 	memcpy(digest, ctx->buf, 16);
-	memset(ctx,0,sizeof(ctx));
+	memset(ctx, 0, sizeof(*ctx));
 }