diff --git a/plugins/CuraEngineBackend/CuraEngineBackend.py b/plugins/CuraEngineBackend/CuraEngineBackend.py
index 646400c2c2..6af51c4cc6 100644
--- a/plugins/CuraEngineBackend/CuraEngineBackend.py
+++ b/plugins/CuraEngineBackend/CuraEngineBackend.py
@@ -127,7 +127,7 @@ class CuraEngineBackend(Backend):
 
     ##  Perform a slice of the scene.
     def slice(self):
-        self.printDurationMessage.emit(0, 0)
+        self.printDurationMessage.emit(0, [0])
 
         self._stored_layer_data = []