diff --git a/plugins/3MFReader/ThreeMFWorkspaceReader.py b/plugins/3MFReader/ThreeMFWorkspaceReader.py
index f3c5a07f82..74589b8335 100755
--- a/plugins/3MFReader/ThreeMFWorkspaceReader.py
+++ b/plugins/3MFReader/ThreeMFWorkspaceReader.py
@@ -738,7 +738,7 @@ class ThreeMFWorkspaceReader(WorkspaceReader):
 
     @staticmethod
     def _loadMetadata(file_name: str) -> Dict[str, Dict[str, Any]]:
-        result = dict()
+        result = dict()  # type: Dict[str, Dict[str, Any]]
         try:
             archive = zipfile.ZipFile(file_name, "r")
         except zipfile.BadZipFile: