diff --git a/cura/CuraApplication.py b/cura/CuraApplication.py
index a6d0a3b827..1142783c9c 100644
--- a/cura/CuraApplication.py
+++ b/cura/CuraApplication.py
@@ -98,7 +98,7 @@ class CuraApplication(QtApplication):
         SettingDefinition.addSupportedProperty("settable_per_meshgroup", DefinitionPropertyType.Any, default = True)
         SettingDefinition.addSupportedProperty("settable_globally", DefinitionPropertyType.Any, default = True)
         SettingDefinition.addSupportedProperty("global_inherits_stack", DefinitionPropertyType.Function, default = "-1")
-        SettingDefinition.addSettingType("extruder", int, str, Validator)
+        SettingDefinition.addSettingType("extruder", None, str, Validator)
 
         ## Add the 4 types of profiles to storage.
         Resources.addStorageType(self.ResourceTypes.QualityInstanceContainer, "quality")