diff --git a/drivers/scsi/hosts.c b/drivers/scsi/hosts.c
index 38c3a291efac..bd8e7f323c69 100644
--- a/drivers/scsi/hosts.c
+++ b/drivers/scsi/hosts.c
@@ -435,7 +435,7 @@ struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
 	struct class_device *cdev;
 	struct Scsi_Host *shost = ERR_PTR(-ENXIO), *p;
 
-	down_read(&class->subsys.rwsem);
+	down(&class->sem);
 	list_for_each_entry(cdev, &class->children, node) {
 		p = class_to_shost(cdev);
 		if (p->host_no == hostnum) {
@@ -443,7 +443,7 @@ struct Scsi_Host *scsi_host_lookup(unsigned short hostnum)
 			break;
 		}
 	}
-	up_read(&class->subsys.rwsem);
+	up(&class->sem);
 
 	return shost;
 }