diff --git a/nomenclature/processor/region.py b/nomenclature/processor/region.py
index d2964650..99764cde 100644
--- a/nomenclature/processor/region.py
+++ b/nomenclature/processor/region.py
@@ -412,9 +412,11 @@ def to_yaml(self, file) -> None:
         }
         if self.native_regions:
             dict_representation["native_regions"] = [
-                {native_region.name: native_region.rename}
-                if native_region.rename
-                else native_region.name
+                (
+                    {native_region.name: native_region.rename}
+                    if native_region.rename
+                    else native_region.name
+                )
                 for native_region in self.native_regions
             ]
         if self.common_regions:
diff --git a/nomenclature/processor/required_data.py b/nomenclature/processor/required_data.py
index edd4012f..010caacb 100644
--- a/nomenclature/processor/required_data.py
+++ b/nomenclature/processor/required_data.py
@@ -42,9 +42,10 @@ def cast_to_RequiredMeasurand(v) -> RequiredMeasurand:
 
 
 class RequiredData(BaseModel):
-    measurand: List[
-        Annotated[RequiredMeasurand, BeforeValidator(cast_to_RequiredMeasurand)]
-    ] | None = None
+    measurand: (
+        List[Annotated[RequiredMeasurand, BeforeValidator(cast_to_RequiredMeasurand)]]
+        | None
+    ) = None
     variable: List[str] | None = None
     region: List[str] | None = None
     year: List[int] | None = None