diff --git a/main/md5.c b/main/md5.c
index 594c5eff5b..cbca747a36 100644
--- a/main/md5.c
+++ b/main/md5.c
@@ -157,7 +157,7 @@ void MD5Final(unsigned char digest[16], struct MD5Context *ctx)
 	MD5Transform(ctx->buf, (uint32_t *) ctx->in);
 	byteReverse((unsigned char *) ctx->buf, 4);
 	memcpy(digest, ctx->buf, 16);
-	memset(ctx, 0, sizeof(ctx));	/* In case it's sensitive */
+	memset(ctx, 0, sizeof(*ctx));	/* In case it's sensitive */
 }
 
 #ifndef ASM_MD5