diff --git a/module/zfs/dmu_tx.c b/module/zfs/dmu_tx.c
index 0af089198c..a9bc1e6ac1 100644
--- a/module/zfs/dmu_tx.c
+++ b/module/zfs/dmu_tx.c
@@ -1103,7 +1103,7 @@ dmu_tx_callback(list_t *cb_list, int error)
 {
 	dmu_tx_callback_t *dcb;
 
-	while (dcb = list_head(cb_list)) {
+	while ((dcb = list_head(cb_list))) {
 		list_remove(cb_list, dcb);
 		dcb->dcb_func(dcb->dcb_data, error);
 		kmem_free(dcb, sizeof (dmu_tx_callback_t));