diff --git a/cura/PrinterOutput/FirmwareUpdater.py b/cura/PrinterOutput/FirmwareUpdater.py
index ca5997bfb1..17089ad17f 100644
--- a/cura/PrinterOutput/FirmwareUpdater.py
+++ b/cura/PrinterOutput/FirmwareUpdater.py
@@ -7,6 +7,7 @@ from UM.Resources import Resources
 from cura.PrinterOutputDevice import PrinterOutputDevice
 
 from enum import IntEnum
+from threading import Thread
 
 class FirmwareUpdater(QObject):
     firmwareProgressChanged = pyqtSignal()