diff --git a/.github/workflows/mypy.yml b/.github/workflows/mypy.yml
index 62cf4201..24d9c34b 100644
--- a/.github/workflows/mypy.yml
+++ b/.github/workflows/mypy.yml
@@ -1,4 +1,4 @@
-name: mypy
+name: lint
 
 on:
   pull_request:
@@ -6,7 +6,7 @@ on:
     branches: [main]
 
 jobs:
-  tox:
+  lint:
     strategy:
       matrix:
         python-version: ["3.8", "3.11"]
@@ -30,5 +30,7 @@ jobs:
         run: python -m pip install --upgrade mypy typing-extensions ruff
       - name: run mypy
         run: cd spec/API_specification && mypy dataframe_api && mypy examples
-      - name: run ruff
-        run: cd spec/API_specification && ruff format dataframe_api examples && ruff dataframe_api examples
+      - name: run ruff format
+        run: cd spec/API_specification && ruff format dataframe_api examples --diff
+      - name: run ruff check
+        run: cd spec/API_specification && ruff check dataframe_api examples --no-fix
diff --git a/spec/API_specification/dataframe_api/typing.py b/spec/API_specification/dataframe_api/typing.py
index 818101ec..39071ca8 100644
--- a/spec/API_specification/dataframe_api/typing.py
+++ b/spec/API_specification/dataframe_api/typing.py
@@ -69,7 +69,7 @@ class NullType:
     null: NullType
 
     class Datetime:
-        time_unit: Literal['ms', 'us']
+        time_unit: Literal["ms", "us"]
         time_zone: str | None
 
         def __init__(  # noqa: ANN204
@@ -80,7 +80,7 @@ def __init__(  # noqa: ANN204
             ...
 
     class Duration:
-        time_unit: Literal['ms', 'us']
+        time_unit: Literal["ms", "us"]
 
         def __init__(  # noqa: ANN204
             self,