diff --git a/pytec/tec_qt.py b/pytec/tec_qt.py
index e2bbc90..7c34377 100644
--- a/pytec/tec_qt.py
+++ b/pytec/tec_qt.py
@@ -138,6 +138,8 @@ class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
     async def closeEvent(self, event):
         if self.client_watcher is not None:
             self.client_watcher.stop_watching()
+        if self.tec_client is not None:
+            await self.tec_client.disconnect()
 
     @asyncSlot()
     async def connect(self):