diff --git a/lib/md5.c b/lib/md5.c
index 306984517..6ad4b6845 100644
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -150,7 +150,7 @@ 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