diff --git a/qmk-cmd.go b/qmk-cmd.go
index f766b1b..021a619 100644
--- a/qmk-cmd.go
+++ b/qmk-cmd.go
@@ -285,8 +285,13 @@ func setCfg(dev *QEncDevice, cfg QEncCfg, val uint8) (err error) {
 }
 
 func sendDataWrapper(dev *QEncDevice, data []byte, cmd QEncCmd, id uint32) (ret []byte, err error) {
-	dev.Lock()
-	defer dev.UnLock()
+	if err = dev.Open(); err != nil {
+		return nil, err
+	}
+	if err = dev.Lock(); err != nil {
+		return nil, err
+	}
+	defer dev.Close()
 
 	done := make(chan bool)
 	msgc := make(chan string)