diff --git a/.gitea/workflows/default.yaml b/.gitea/workflows/default.yaml
index efb9e33..cb1c16d 100644
--- a/.gitea/workflows/default.yaml
+++ b/.gitea/workflows/default.yaml
@@ -25,4 +25,6 @@ jobs:
       - name: PEP8 check
         run: flake8 ./code --benchmark
       - name: Type check
-        run: mypy ./code
\ No newline at end of file
+        run: |
+          python3 -m pip install types-python-dateutil
+          mypy ./code
\ No newline at end of file
diff --git a/.gitea/workflows/release.yaml b/.gitea/workflows/release.yaml
index e515794..4f801b8 100644
--- a/.gitea/workflows/release.yaml
+++ b/.gitea/workflows/release.yaml
@@ -24,7 +24,9 @@ jobs:
       - name: PEP8 check
         run: flake8 ./code --benchmark
       - name: Type check
-        run: mypy ./code
+        run: |
+          python3 -m pip install types-python-dateutil
+          mypy ./code
   publish:
     name: Publish
     runs-on: ubuntu-latest