diff --git a/.github/workflows/notebook-interfaces-test.yml b/.github/workflows/notebook-interfaces-test.yml
index 56aac7745..e5fb44802 100644
--- a/.github/workflows/notebook-interfaces-test.yml
+++ b/.github/workflows/notebook-interfaces-test.yml
@@ -17,6 +17,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
+          # Testing on version that Stan currently supports
           python-version: '3.12'
 
       # We use e.g. install pints[stan] to install dependencies for interfaces
diff --git a/.github/workflows/unit-test-os-coverage.yml b/.github/workflows/unit-test-os-coverage.yml
index 6014026be..9fb4ad5d1 100644
--- a/.github/workflows/unit-test-os-coverage.yml
+++ b/.github/workflows/unit-test-os-coverage.yml
@@ -21,8 +21,8 @@ jobs:
 
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-latest, windows-latest]
-        # Note: Ubuntu 22 is checked by other tests
+        os: [ubuntu-22.04, macos-latest, windows-latest]
+        # Note: Ubuntu 24 is checked by other tests
 
     steps:
       - uses: actions/checkout@v4
diff --git a/.github/workflows/upload-to-pypi.yml b/.github/workflows/upload-to-pypi.yml
index 8f3d0f0e3..50565dc48 100644
--- a/.github/workflows/upload-to-pypi.yml
+++ b/.github/workflows/upload-to-pypi.yml
@@ -17,7 +17,7 @@ jobs:
       - name: Set up Python
         uses: actions/setup-python@v5
         with:
-          python-version: '3.11'
+          python-version: '3.13'
 
       - name: install dependencies
         run: |