diff --git a/dsa-sign.c b/dsa-sign.c
index a22b0a52a3674836616d2185945bf33bc83a3872..3a69a216c35f903ba1780c92d5b407f92c1569e3 100644
--- a/dsa-sign.c
+++ b/dsa-sign.c
@@ -94,6 +94,7 @@ dsa_sign(struct dsa_private_key *key,
   mpz_fdiv_r(signature->r, tmp, key->pub.q);
 
   /* Compute hash */
+  mpz_init(h);
   _dsa_hash(h, hash);
 
   /* Compute k^-1 (mod q) */