diff --git a/libs/partners/openai/langchain_openai/chat_models/base.py b/libs/partners/openai/langchain_openai/chat_models/base.py
index 7cb80a7f134..9cd4161ec88 100644
--- a/libs/partners/openai/langchain_openai/chat_models/base.py
+++ b/libs/partners/openai/langchain_openai/chat_models/base.py
@@ -3895,7 +3895,7 @@ def _convert_responses_chunk_to_generation_chunk(
                     "type": "text",
                     "text": "",
                     "annotations": [annotation],
-                    "index": current_index
+                    "index": current_index,
                 }
             )
         else:
diff --git a/libs/partners/openai/tests/integration_tests/chat_models/test_responses_api.py b/libs/partners/openai/tests/integration_tests/chat_models/test_responses_api.py
index abe7afb706a..2db68db409f 100644
--- a/libs/partners/openai/tests/integration_tests/chat_models/test_responses_api.py
+++ b/libs/partners/openai/tests/integration_tests/chat_models/test_responses_api.py
@@ -184,7 +184,9 @@ class FooDict(TypedDict):
 @pytest.mark.default_cassette("test_parsed_pydantic_schema.yaml.gz")
 @pytest.mark.vcr
 @pytest.mark.parametrize("output_version", ["v0", "responses/v1", "v1"])
-def test_parsed_pydantic_schema(output_version: Literal["v0", "responses/v1", "v1"]) -> None:
+def test_parsed_pydantic_schema(
+    output_version: Literal["v0", "responses/v1", "v1"],
+) -> None:
     llm = ChatOpenAI(
         model=MODEL_NAME, use_responses_api=True, output_version=output_version
     )
@@ -458,9 +460,7 @@ def test_stream_reasoning_summary(
 @pytest.mark.default_cassette("test_code_interpreter.yaml.gz")
 @pytest.mark.vcr
 @pytest.mark.parametrize("output_version", ["v0", "responses/v1", "v1"])
-def test_code_interpreter(
-    output_version: Literal["v0", "responses/v1", "v1"],
-) -> None:
+def test_code_interpreter(output_version: Literal["v0", "responses/v1", "v1"]) -> None:
     llm = ChatOpenAI(
         model="o4-mini", use_responses_api=True, output_version=output_version
     )