diff --git a/plugins/3MFReader/ThreeMFWorkspaceReader.py b/plugins/3MFReader/ThreeMFWorkspaceReader.py
index b775d0055c..0c1bd0a9a2 100755
--- a/plugins/3MFReader/ThreeMFWorkspaceReader.py
+++ b/plugins/3MFReader/ThreeMFWorkspaceReader.py
@@ -934,7 +934,8 @@ class ThreeMFWorkspaceReader(WorkspaceReader):
         :return: The count of the machine's extruders
         """
         machine_extruder_count = None
-        if self._machine_info.definition_changes_info \
+        if self._machine_info \
+                and self._machine_info.definition_changes_info \
                 and "values" in self._machine_info.definition_changes_info.parser \
                 and "machine_extruder_count" in self._machine_info.definition_changes_info.parser["values"]:
             try: