diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 5c96949..70ec79d 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -51,6 +51,12 @@ jobs:
       run: |
         pip install black
         black --check --diff .
+    - name: Check types
+      # TODO(https://github.com/google/pytype/issues/1308): Remove condition.
+      if: matrix.python-version != '3.11'
+      run: |
+        pip install pytype
+        pytype
     - name: Test
       run: |
         pip install pytest pytest-cov
diff --git a/pyproject.toml b/pyproject.toml
index c9d7bc8..ff77fd7 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -33,6 +33,13 @@ addopts = """\
   --cov-report=term-missing \
   """
 
+[tool.pytype]
+inputs = ["."]
+exclude = [
+  "**/*_pb2.pyi",
+]
+jobs = "auto"
+
 [tool.setuptools-protobuf]
 protobufs = [
   "rock_paper_sand/proto/config.proto",