diff --git a/plugins/3MFReader/__init__.py b/plugins/3MFReader/__init__.py
index 5e2b68fce0..d468783a90 100644
--- a/plugins/3MFReader/__init__.py
+++ b/plugins/3MFReader/__init__.py
@@ -23,7 +23,7 @@ def getMetaData() -> Dict:
     if "3MFReader.ThreeMFReader" in sys.modules:
         metaData["mesh_reader"] = [
             {
-                "extension": "3mf",
+                "extension": workspace_extension,
                 "description": catalog.i18nc("@item:inlistbox", "3MF File")
             }
         ]
diff --git a/plugins/3MFWriter/ThreeMFWriter.py b/plugins/3MFWriter/ThreeMFWriter.py
index be0fa1a01b..61aec6b664 100644
--- a/plugins/3MFWriter/ThreeMFWriter.py
+++ b/plugins/3MFWriter/ThreeMFWriter.py
@@ -10,8 +10,6 @@ import threading
 
 from typing import Optional, cast, List, Dict, Pattern, Set
 
-from Machines.Models.ExtrudersModel import ExtrudersModel
-from Settings.ExtruderStack import ExtruderStack
 from UM.PluginRegistry import PluginRegistry
 from UM.Mesh.MeshWriter import MeshWriter
 from UM.Math.Vector import Vector
@@ -26,7 +24,9 @@ from UM.Settings.ContainerRegistry import ContainerRegistry
 
 from cura.CuraApplication import CuraApplication
 from cura.CuraPackageManager import CuraPackageManager
+from cura.Machines.Models.ExtrudersModel import ExtrudersModel
 from cura.Settings import CuraContainerStack
+from cura.Settings.ExtruderStack import ExtruderStack
 from cura.Utils.Threading import call_on_qt_thread
 from cura.Scene.CuraSceneNode import CuraSceneNode
 from cura.Snapshot import Snapshot