diff --git a/src/drivers/infiniband/qib7322.c b/src/drivers/infiniband/qib7322.c
index b66f8ef..d8a54c9 100644
--- a/src/drivers/infiniband/qib7322.c
+++ b/src/drivers/infiniband/qib7322.c
@@ -2120,7 +2120,7 @@ static int qib7322_ahb_write ( struct qib7322 *qib7322, unsigned int location,
  */
 static int qib7322_ahb_mod_reg ( struct qib7322 *qib7322, unsigned int location,
 				 uint32_t value, uint32_t mask ) {
-	uint32_t old_value;
+	uint32_t old_value = 0;
 	uint32_t new_value;
 	int rc;