diff --git a/drivers/ata/ahci.c b/drivers/ata/ahci.c
index f2522534ae63..fe75d8befc3a 100644
--- a/drivers/ata/ahci.c
+++ b/drivers/ata/ahci.c
@@ -1042,7 +1042,7 @@ static int ahci_init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	VPRINTK("ENTER\n");
 
-	WARN_ON(ATA_MAX_QUEUE > AHCI_MAX_CMDS);
+	WARN_ON((int)ATA_MAX_QUEUE > AHCI_MAX_CMDS);
 
 	if (!printed_version++)
 		dev_printk(KERN_DEBUG, &pdev->dev, "version " DRV_VERSION "\n");