diff --git a/pkg/util/aws/instance.go b/pkg/util/aws/instance.go
index 310443d6cb..c2ae141911 100644
--- a/pkg/util/aws/instance.go
+++ b/pkg/util/aws/instance.go
@@ -667,20 +667,20 @@ func (self *SRegion) ChangeVMConfig(zoneId string, instanceId string, ncpu int,
 	return nil
 }
 
-func (self *SRegion) DetachDisk(instanceId string, diskId string, deviceName string) error {
+func (self *SRegion) DetachDisk(instanceId string, diskId string) error {
 	params := &ec2.DetachVolumeInput{}
 	params.SetInstanceId(instanceId)
 	params.SetVolumeId(diskId)
-	params.SetDevice(deviceName)
 
 	_, err := self.ec2Client.DetachVolume(params)
 	return err
 }
 
-func (self *SRegion) AttachDisk(instanceId string, diskId string) error {
+func (self *SRegion) AttachDisk(instanceId string, diskId string, deviceName string) error {
 	params := &ec2.AttachVolumeInput{}
 	params.SetInstanceId(instanceId)
 	params.SetVolumeId(diskId)
+	params.SetDevice(deviceName)
 
 	_, err := self.ec2Client.AttachVolume(params)
 	return err
diff --git a/pkg/util/aws/shell/instance.go b/pkg/util/aws/shell/instance.go
index d342daa17c..12942fe16e 100644
--- a/pkg/util/aws/shell/instance.go
+++ b/pkg/util/aws/shell/instance.go
@@ -52,8 +52,14 @@ func init() {
 		DISK string `help:"disk ID"`
 	}
 
-	shellutils.R(&InstanceDiskOperationOptions{}, "instance-attach-disk", "Attach a disk to instance", func(cli *aws.SRegion, args *InstanceDiskOperationOptions) error {
-		err := cli.AttachDisk(args.ID, args.DISK)
+	type InstanceDiskAttachOptions struct {
+		ID   string `help:"instance ID"`
+		DISK string `help:"disk ID"`
+		DEVICE string `help:"disk device name. eg. /dev/sdb"`
+	}
+
+	shellutils.R(&InstanceDiskAttachOptions{}, "instance-attach-disk", "Attach a disk to instance", func(cli *aws.SRegion, args *InstanceDiskOperationOptions) error {
+		err := cli.AttachDisk(args.ID, args.DISK, args.DEVICE)
 		if err != nil {
 			return err
 		}