diff --git a/src/ifcopenshell-python/ifcopenshell/file.py b/src/ifcopenshell-python/ifcopenshell/file.py
index 29c991e0e7..1b67adbefb 100644
--- a/src/ifcopenshell-python/ifcopenshell/file.py
+++ b/src/ifcopenshell-python/ifcopenshell/file.py
@@ -35,7 +35,7 @@ if TYPE_CHECKING:
 HEADER_FIELDS = {
     "file_description": [
         "description",
-        "implementation_level"
+        "implementation_level",
     ],
     "file_name": [
         "name",
@@ -44,10 +44,11 @@ HEADER_FIELDS = {
         "organization",
         "preprocessor_version",
         "originating_system",
-        "authorization"
-    ]
+        "authorization",
+    ],
 }
 
+
 class Transaction:
     def __init__(self, ifc_file):
         self.file = ifc_file