diff --git a/lib/md5.c b/lib/md5.c
index d8344dbe4..af39fd41a 100644
--- a/lib/md5.c
+++ b/lib/md5.c
@@ -147,7 +147,7 @@ static void MD5_Update(MD5_CTX *ctx,
 
 static void MD5_Final(unsigned char digest[16], MD5_CTX *ctx)
 {
-  unsigned long length;
+  unsigned long length = 0;
   CryptGetHashParam(ctx->hHash, HP_HASHVAL, NULL, &length, 0);
   if(length == 16)
     CryptGetHashParam(ctx->hHash, HP_HASHVAL, digest, &length, 0);