diff --git a/.github/workflows/build_pkg_runner.yml b/.github/workflows/build_pkg_runner.yml
index cf12b9e..2feefee 100644
--- a/.github/workflows/build_pkg_runner.yml
+++ b/.github/workflows/build_pkg_runner.yml
@@ -7,11 +7,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
         matrix:
-          os: [ubuntu-20.04, macos-latest]
+          os: [ubuntu-24.04, macos-latest]
         fail-fast: false
     steps:
     - name: Checkout Repository
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         fetch-depth: 1
     - name: Scotch - tarball build
diff --git a/.github/workflows/shunit2_runner.yml b/.github/workflows/shunit2_runner.yml
index c2b62dc..b62fc9c 100644
--- a/.github/workflows/shunit2_runner.yml
+++ b/.github/workflows/shunit2_runner.yml
@@ -7,11 +7,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
       matrix:
-        os: [ubuntu-20.04, macos-15]
+        os: [ubuntu-24.04, macos-15]
       fail-fast: false
     steps:
       - name: Checkout repository
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
       - name: Checkout submodules
         run: git submodule update --init --recursive
       - name: Unittest
diff --git a/.github/workflows/solvcon_runner.yml b/.github/workflows/solvcon_runner.yml
index 894cffc..cd711bd 100644
--- a/.github/workflows/solvcon_runner.yml
+++ b/.github/workflows/solvcon_runner.yml
@@ -7,11 +7,11 @@ jobs:
     runs-on: ${{ matrix.os }}
     strategy:
         matrix:
-          os: [ubuntu-20.04, macos-latest]
+          os: [ubuntu-24.04, macos-latest]
         fail-fast: false
     steps:
     - name: Checkout Repository
-      uses: actions/checkout@v2
+      uses: actions/checkout@v4
       with:
         fetch-depth: 1
     - name: Set DEVENV_WORKSPACE