diff --git a/src/osmg/load_case.py b/src/osmg/load_case.py
index 90c25c79..d6f42430 100644
--- a/src/osmg/load_case.py
+++ b/src/osmg/load_case.py
@@ -186,8 +186,12 @@ class LoadCase:
 
     name: str
     parent_model: Model
-    node_loads: obj_collections.Collection[int, PointLoadMass] = field(init=False)
-    node_mass: obj_collections.Collection[int, PointLoadMass] = field(init=False)
+    node_loads: obj_collections.Collection[int, PointLoadMass] = field(
+        init=False
+    )
+    node_mass: obj_collections.Collection[int, PointLoadMass] = field(
+        init=False
+    )
     line_element_udl: obj_collections.Collection[int, LineElementUDL] = field(
         init=False
     )
diff --git a/src/osmg/model.py b/src/osmg/model.py
index 808793d8..24ae99df 100644
--- a/src/osmg/model.py
+++ b/src/osmg/model.py
@@ -122,15 +122,12 @@ class Model:
     elastic_sections: obj_collections.Collection[int, ElasticSection] = field(
         init=False
     )
-    fiber_sections: obj_collections.Collection[int, FiberSection] = field(
-        init=False
-    )
-    uniaxial_materials: obj_collections.Collection[int, UniaxialMaterial] = field(
-        init=False
-    )
-    physical_materials: obj_collections.Collection[int, PhysicalMaterial] = field(
-        init=False
-    )
+    fiber_sections: obj_collections.Collection[
+        int, FiberSection] = field(init=False)
+    uniaxial_materials: obj_collections.Collection[
+        int, UniaxialMaterial] = field(init=False)
+    physical_materials: obj_collections.Collection[
+        int, PhysicalMaterial] = field(init=False)
     uid_generator: UIDGenerator = field(default_factory=UIDGenerator)
     settings: Settings = field(default_factory=Settings)