diff --git a/lib/sha256.c b/lib/sha256.c
index a3be92a4e..aebcc55b2 100644
--- a/lib/sha256.c
+++ b/lib/sha256.c
@@ -224,6 +224,7 @@ static void SHA256_Update(SHA256_CTX *ctx,
 static void SHA256_Final(unsigned char *digest, SHA256_CTX *ctx)
 {
   unsigned long length;
+  length = 0;
 
   CryptGetHashParam(ctx->hHash, HP_HASHVAL, NULL, &length, 0);
   if(length == SHA256_DIGEST_LENGTH)