diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2fb12d5..53143e6 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -56,9 +56,10 @@ jobs:
     timeout-minutes: 45
 
     strategy:
+      fail-fast: false
       matrix:
         python-version: ['3.9', '3.10', '3.11', '3.12']
-        os: [ubuntu-24.04]
+        os: [ubuntu-latest]
         include:
         - os: macos-latest
           python-version: '3.12'
@@ -67,9 +68,6 @@ jobs:
 
     name: ${{ matrix.os }} Python ${{ matrix.python-version }}
 
-    env:
-      FC: gfortran-13
-
     steps:
 
     - uses: actions/setup-python@v5
diff --git a/.github/workflows/composite-gemini3d/action.yml b/.github/workflows/composite-gemini3d/action.yml
index edad706..c4782f5 100644
--- a/.github/workflows/composite-gemini3d/action.yml
+++ b/.github/workflows/composite-gemini3d/action.yml
@@ -4,6 +4,14 @@ runs:
 
     steps:
 
+    - name: GCC compiler (macOS)
+      shell: bash
+      if: runner.os == 'macOS'
+      run: |
+        echo "CC=gcc-13" >> $GITHUB_ENV
+        echo "CXX=g++-13" >> $GITHUB_ENV
+        echo "FC=gfortran-13" >> $GITHUB_ENV
+
     - name: Checkout GemGI (for simulation config.nml inputs)
       uses: actions/checkout@v4
       with: