diff --git a/src/primaite/simulator/file_system/file_system.py b/src/primaite/simulator/file_system/file_system.py
index 1346d3e0..e9385644 100644
--- a/src/primaite/simulator/file_system/file_system.py
+++ b/src/primaite/simulator/file_system/file_system.py
@@ -211,7 +211,7 @@ class FileSystem(SimComponent):
             if file is not None:
                 return file
 
-    def get_folder_by_name(self, folder_name: str) -> Union[FileSystemFolder, None]:
+    def get_folder_by_name(self, folder_name: str) -> Optional[FileSystemFolder]:
         """
         Returns a the first folder with a matching name.