diff --git a/.github/workflows/mypy.yaml b/.github/workflows/mypy.yaml
index 4781688..b8ab802 100644
--- a/.github/workflows/mypy.yaml
+++ b/.github/workflows/mypy.yaml
@@ -22,7 +22,7 @@ jobs:
       - name: Setup python
         uses: https://github.com/actions/setup-python@v5
         with:
-          python-version: "3.12"
+          python-version: ${{ matrix.python-version }}
       - name: Install uv
         uses: https://github.com/astral-sh/setup-uv@v5
       - name: Install corrlib
diff --git a/.github/workflows/ruff.yaml b/.github/workflows/ruff.yaml
index e0db1b0..778743b 100644
--- a/.github/workflows/ruff.yaml
+++ b/.github/workflows/ruff.yaml
@@ -23,7 +23,7 @@ jobs:
       - name: Setup python
         uses: https://github.com/actions/setup-python@v5
         with:
-          python-version: "3.12"
+          python-version: ${{ matrix.python-version }}
       - name: Install uv
         uses: https://github.com/astral-sh/setup-uv@v5
       - name: Install corrlib
diff --git a/corrlib/find.py b/corrlib/find.py
index 022a3f5..21063ec 100644
--- a/corrlib/find.py
+++ b/corrlib/find.py
@@ -119,7 +119,7 @@ def _db_lookup(db: str, ensemble: str, correlator_name: str, code: str, project:
 
 
 def sfcf_filter(results: pd.DataFrame, **kwargs: Any) -> pd.DataFrame:
-    r"""
+    """
     Filter method for the Database entries holding SFCF calculations.
 
     Parameters
diff --git a/corrlib/meas_io.py b/corrlib/meas_io.py
index 2a8c986..300adc3 100644
--- a/corrlib/meas_io.py
+++ b/corrlib/meas_io.py
@@ -12,7 +12,7 @@ import shutil
 from typing import Any
 
 
-def write_measurement(path: str, ensemble: str, measurement: dict[str, dict[str, dict[str, Any]]], uuid: str, code: str, parameter_file: Union(Any, None)) -> None:
+def write_measurement(path: str, ensemble: str, measurement: dict[str, dict[str, dict[str, Any]]], uuid: str, code: str, parameter_file: str) -> None:
     """
     Write a measurement to the backlog.
     If the file for the measurement already exists, update the measurement.