diff --git a/plugins/CuraEngineBackend/CuraEngineBackend.py b/plugins/CuraEngineBackend/CuraEngineBackend.py
index 91a9ee0e7b..58bc74f3f1 100755
--- a/plugins/CuraEngineBackend/CuraEngineBackend.py
+++ b/plugins/CuraEngineBackend/CuraEngineBackend.py
@@ -179,8 +179,7 @@ class CuraEngineBackend(QObject, Backend):
     #   This is useful for debugging and used to actually start the engine.
     #   \return list of commands and args / parameters.
     def getEngineCommand(self) -> List[str]:
-        json_path = Resources.getPath(Resources.DefinitionContainers, "fdmprinter.def.json")
-        command = [self._application.getPreferences().getValue("backend/location"), "connect", "127.0.0.1:{0}".format(self._port), "-j", json_path, ""]
+        command = [self._application.getPreferences().getValue("backend/location"), "connect", "127.0.0.1:{0}".format(self._port), ""]
 
         parser = argparse.ArgumentParser(prog = "cura", add_help = False)
         parser.add_argument("--debug", action = "store_true", default = False, help = "Turn on the debug mode by setting this option.")
diff --git a/plugins/CuraEngineBackend/StartSliceJob.py b/plugins/CuraEngineBackend/StartSliceJob.py
index 28e442033b..dd0d9db0a2 100644
--- a/plugins/CuraEngineBackend/StartSliceJob.py
+++ b/plugins/CuraEngineBackend/StartSliceJob.py
@@ -440,8 +440,7 @@ class StartSliceJob(Job):
             Job.yieldThread()
 
         # Ensure that the engine is aware what the build extruder is.
-        if stack.getProperty("machine_extruder_count", "value") > 1:
-            changed_setting_keys.add("extruder_nr")
+        changed_setting_keys.add("extruder_nr")
 
         # Get values for all changed settings
         for key in changed_setting_keys:
diff --git a/resources/definitions/fdmprinter.def.json b/resources/definitions/fdmprinter.def.json
index 2ca15ab646..823635a62a 100644
--- a/resources/definitions/fdmprinter.def.json
+++ b/resources/definitions/fdmprinter.def.json
@@ -230,6 +230,7 @@
                     "label": "Number of Extruders that are enabled",
                     "description": "Number of extruder trains that are enabled; automatically set in software",
                     "value": "machine_extruder_count",
+                    "default_value": 1,
                     "minimum_value": "1",
                     "maximum_value": "16",
                     "type": "int",