diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 05882e4445a6..7137e1bbf04a 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -53,7 +53,7 @@
 
 enum {
 	AHCI_MAX_PORTS		= 32,
-	AHCI_MAX_CLKS		= 3,
+	AHCI_MAX_CLKS		= 4,
 	AHCI_MAX_SG		= 168, /* hardware max is 64K */
 	AHCI_DMA_BOUNDARY	= 0xffffffff,
 	AHCI_MAX_CMDS		= 32,