diff --git a/action_create.go b/action_create.go
index 36413d8..eebbd0e 100644
--- a/action_create.go
+++ b/action_create.go
@@ -61,16 +61,16 @@ func (s Service) Create(payload CreateOptions) error {
 func (payload CreateOptions) newDevice() (result Device, err error) {
 	timeNow := now()
 	device := Device{
-		ID:             mongodb.NewObjectID(),
-		DeviceID:       payload.DeviceID,
-		OSName:         getOSName(payload.UserAgent),
-		OSVersion:      getOSVersion(payload.UserAgent),
-		IP:             payload.IP,
-		Language:       getLanguage(payload.Language),
-		AuthToken:      payload.AuthToken,
-		LastActivityAt: timeNow,
-		CreatedAt:      timeNow,
-		FCMToken:       payload.FCMToken,
+		ID:              mongodb.NewObjectID(),
+		DeviceID:        payload.DeviceID,
+		OSName:          getOSName(payload.UserAgent),
+		OSVersion:       getOSVersion(payload.UserAgent),
+		IP:              payload.IP,
+		Language:        getLanguage(payload.Language),
+		AuthToken:       payload.AuthToken,
+		LastActivatedAt: timeNow,
+		CreatedAt:       timeNow,
+		FCMToken:        payload.FCMToken,
 	}
 
 	// App version
diff --git a/helper.go b/helper.go
index 3441415..120e9d5 100644
--- a/helper.go
+++ b/helper.go
@@ -26,12 +26,9 @@ func (s Service) isDeviceIDExisted(ctx context.Context, deviceID string) bool {
 			"deviceID": deviceID,
 			"err":      err.Error(),
 		})
-	}
-	if !device.ID.IsZero() {
 		return true
 	}
-
-	return false
+	return !device.ID.IsZero()
 }
 
 func getOSName(userAgent string) string {
diff --git a/model.go b/model.go
index 33dce53..7c00d78 100644
--- a/model.go
+++ b/model.go
@@ -8,17 +8,17 @@ import (
 
 // Device ...
 type Device struct {
-	ID             primitive.ObjectID `bson:"_id" json:"_id"`
-	DeviceID       string             `bson:"deviceID" json:"deviceId"` // unique
-	IP             string             `bson:"ip" json:"ip"`
-	OSName         string             `bson:"osName" json:"osName"`
-	OSVersion      string             `bson:"osVersion" json:"osVersion"`
-	AppVersion     string             `bson:"appVersion" json:"appVersion"`
-	Language       string             `bson:"language" json:"language"` // vi, en
-	IsMobile       bool               `bson:"isMobile" json:"isMobile"`
-	LastActivityAt time.Time          `bson:"lastActivityAt" json:"lastActivityAt"`
-	UserID         primitive.ObjectID `bson:"userID" json:"userId"`
-	AuthToken      string             `bson:"authToken" json:"authToken"`
-	FCMToken       string             `bson:"fcmToken" json:"fcmToken"`
-	CreatedAt      time.Time          `bson:"createdAt" json:"createdAt"`
+	ID              primitive.ObjectID `bson:"_id" json:"_id"`
+	DeviceID        string             `bson:"deviceID" json:"deviceId"` // unique
+	IP              string             `bson:"ip" json:"ip"`
+	OSName          string             `bson:"osName" json:"osName"`
+	OSVersion       string             `bson:"osVersion" json:"osVersion"`
+	AppVersion      string             `bson:"appVersion" json:"appVersion"`
+	Language        string             `bson:"language" json:"language"` // vi, en
+	IsMobile        bool               `bson:"isMobile" json:"isMobile"`
+	LastActivatedAt time.Time          `bson:"lastActivatedAt" json:"lastActivatedAt"`
+	UserID          primitive.ObjectID `bson:"userID" json:"userId"`
+	AuthToken       string             `bson:"authToken" json:"authToken"`
+	FCMToken        string             `bson:"fcmToken" json:"fcmToken"`
+	CreatedAt       time.Time          `bson:"createdAt" json:"createdAt"`
 }