diff --git a/drivers/mailbox/mailbox.c b/drivers/mailbox/mailbox.c
index 30eafdf3a91e..bbc9fd75a95f 100644
--- a/drivers/mailbox/mailbox.c
+++ b/drivers/mailbox/mailbox.c
@@ -526,8 +526,7 @@ int mbox_controller_register(struct mbox_controller *mbox)
 {
 	int i, txdone;
 
-	/* Sanity check */
-	if (!mbox || !mbox->dev || !mbox->ops || !mbox->num_chans)
+	if (!mbox || !mbox->dev || !mbox->ops || !mbox->chans || !mbox->num_chans)
 		return -EINVAL;
 
 	if (mbox->txdone_irq)