diff --git a/daemon/graphdriver/devmapper/deviceset.go b/daemon/graphdriver/devmapper/deviceset.go
index b193480459..e661dbb7ad 100644
--- a/daemon/graphdriver/devmapper/deviceset.go
+++ b/daemon/graphdriver/devmapper/deviceset.go
@@ -62,25 +62,25 @@ type MetaData struct {
 }
 
 type DeviceSet struct {
-	MetaData		`json:"-"`
-	sync.Mutex       	`json:"-"` // Protects Devices map and serializes calls into libdevmapper
-	root             string	`json:"-"`
-	devicePrefix     string	`json:"-"`
-	TransactionId    uint64	`json:"-"`
-	NewTransactionId uint64 `json:"-"`
-	NextDeviceId     int	`json:"next_device_id"`
+	MetaData         `json:"-"`
+	sync.Mutex       `json:"-"` // Protects Devices map and serializes calls into libdevmapper
+	root             string     `json:"-"`
+	devicePrefix     string     `json:"-"`
+	TransactionId    uint64     `json:"-"`
+	NewTransactionId uint64     `json:"-"`
+	NextDeviceId     int        `json:"next_device_id"`
 
 	// Options
-	dataLoopbackSize     int64	`json:"-"`
-	metaDataLoopbackSize int64	`json:"-"`
-	baseFsSize           uint64	`json:"-"`
-	filesystem           string	`json:"-"`
-	mountOptions         string	`json:"-"`
-	mkfsArgs             []string	`json:"-"`
-	dataDevice           string	`json:"-"`
-	metadataDevice       string	`json:"-"`
-	doBlkDiscard         bool	`json:"-"`
-	thinpBlockSize       uint32	`json:"-"`
+	dataLoopbackSize     int64    `json:"-"`
+	metaDataLoopbackSize int64    `json:"-"`
+	baseFsSize           uint64   `json:"-"`
+	filesystem           string   `json:"-"`
+	mountOptions         string   `json:"-"`
+	mkfsArgs             []string `json:"-"`
+	dataDevice           string   `json:"-"`
+	metadataDevice       string   `json:"-"`
+	doBlkDiscard         bool     `json:"-"`
+	thinpBlockSize       uint32   `json:"-"`
 }
 
 type DiskUsage struct {