diff --git a/mypy/stubgenc.py b/mypy/stubgenc.py
index 660ca31416a4a..b2c58b692f6af 100755
--- a/mypy/stubgenc.py
+++ b/mypy/stubgenc.py
@@ -307,7 +307,9 @@ def get_annotation(key: str) -> str | None:
         arglist: list[ArgSig] = []
 
         # Add the arguments to the signature
-        def add_args(args: list[str], get_default_value: Callable[[int, str], object | None]) -> None:
+        def add_args(
+            args: list[str], get_default_value: Callable[[int, str], object | None]
+        ) -> None:
             for i, arg in enumerate(args):
                 # Check if the argument has a default value
                 default_value = get_default_value(i, arg)
diff --git a/mypy/test/teststubgen.py b/mypy/test/teststubgen.py
index 71bbbc5d9420b..77a9f0942811f 100644
--- a/mypy/test/teststubgen.py
+++ b/mypy/test/teststubgen.py
@@ -847,7 +847,9 @@ class TestClassVariableCls:
 
     def test_non_c_generate_signature_with_kw_only_args(self) -> None:
         class TestClass:
-            def test(self, arg0: str, *, keyword_only: str, keyword_only_with_default: int = 7) -> None:
+            def test(
+                self, arg0: str, *, keyword_only: str, keyword_only_with_default: int = 7
+            ) -> None:
                 pass
 
         output: list[str] = []