diff --git a/.github/workflows/mpet-code-style.yml b/.github/workflows/mpet-code-style.yml
index e8ead7be..d3030839 100644
--- a/.github/workflows/mpet-code-style.yml
+++ b/.github/workflows/mpet-code-style.yml
@@ -9,13 +9,13 @@ jobs:
 
     steps:
       - name: Set up python
-        uses: actions/setup-python@v4
+        uses: actions/setup-python@v5
         with:
-          python-version: 3.9
+          python-version: 3.12
           architecture: x64
       
       - name: Checkout MPET
-        uses: actions/checkout@v3
+        uses: actions/checkout@v4
         with:
           fetch-depth: 1
           path: mpet
diff --git a/.github/workflows/mpet-regression-test-sourceforge-daetools.yml b/.github/workflows/mpet-regression-test-sourceforge-daetools.yml
index a9cc1f57..902f765f 100644
--- a/.github/workflows/mpet-regression-test-sourceforge-daetools.yml
+++ b/.github/workflows/mpet-regression-test-sourceforge-daetools.yml
@@ -23,7 +23,6 @@ jobs:
     - uses: actions/setup-python@v5
       with:
         python-version: ${{ matrix.python-version }}
-        activate-environment: mpet-env
 
     - name: Install additional dependencies using mpet's setup.py
       run: |