diff --git a/plugins/UM3NetworkPrinting/src/UM3OutputDevicePlugin.py b/plugins/UM3NetworkPrinting/src/UM3OutputDevicePlugin.py
index a748de8cf2..2d74c8acbb 100644
--- a/plugins/UM3NetworkPrinting/src/UM3OutputDevicePlugin.py
+++ b/plugins/UM3NetworkPrinting/src/UM3OutputDevicePlugin.py
@@ -22,6 +22,8 @@ from UM.i18n import i18nCatalog
 from . import ClusterUM3OutputDevice, LegacyUM3OutputDevice
 from .Cloud.CloudOutputDeviceManager import CloudOutputDeviceManager
 
+from typing import Optional
+
 i18n_catalog = i18nCatalog("cura")
 
 ##      This plugin handles the connection detection & creation of output device objects for the UM3 printer.