diff --git a/src/pkcs11/mechanism.c b/src/pkcs11/mechanism.c
index c4916d38..3b5cd8d2 100644
--- a/src/pkcs11/mechanism.c
+++ b/src/pkcs11/mechanism.c
@@ -389,7 +389,7 @@ sc_pkcs11_signature_size(sc_pkcs11_operation_t *operation, CK_ULONG_PTR pLength)
 {
 	struct sc_pkcs11_object *key;
 	CK_ATTRIBUTE attr = { CKA_MODULUS_BITS, pLength, sizeof(*pLength) };
-	CK_RV rc;
+	CK_RV rv;
 
 	key = ((struct signature_data *) operation->priv_data)->key;
 	rv = key->ops->get_attribute(operation->session, key, &attr);