diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 8d76536ba..c6a8f9763 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -8,6 +8,9 @@ on:
     types: [published]
   schedule:
     - cron: '0 2 * * 3,6'
+
+# runner images:
+# https://github.com/actions/runner-images
 jobs:
   run-unit-and-integration-tests-with-conda-install:
     runs-on: ${{ matrix.os }}
@@ -18,10 +21,10 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-latest",
-             "macos-13",
+             "macos-latest",
              # "windows-latest" # rrcovNA cannot be build from source on windows-server
              ]
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12"]
     steps:
     - name: Checkout
       uses: actions/checkout@v4
@@ -76,7 +79,7 @@ jobs:
       fail-fast: false
       matrix:
         os: ["ubuntu-latest", "macos-latest", "windows-latest"]
-        python-version: ["3.9", "3.10", "3.11", "3.12"]
+        python-version: ["3.10", "3.11", "3.12"]
     steps:
       - uses: actions/checkout@v4
         with: