diff --git a/drivers/ata/ahci.h b/drivers/ata/ahci.h
index 52d0851653e5f9c33f76caa475179c15da04b321..ae69409d316e4b1b260ddf070d8baca7365934aa 100644
--- a/drivers/ata/ahci.h
+++ b/drivers/ata/ahci.h
@@ -266,7 +266,7 @@ enum {
 	PCS_7				= 0x94, /* 7+ port PCS (Denverton) */
 
 	/* em constants */
-	EM_MAX_SLOTS			= 8,
+	EM_MAX_SLOTS			= SATA_PMP_MAX_PORTS,
 	EM_MAX_RETRY			= 5,
 
 	/* em_ctl bits */