diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index a02f8b1..edd67ac 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -28,7 +28,14 @@ jobs:
 
     steps:
       - name: Checkout Mule
-        uses: actions/checkout@v4
+        uses: actions/checkout@v6
+        with:
+          path: mule
+      - name: Checkout Shumlib
+        uses: actions/checkout@v6
+        with:
+          repository: "MetOffice/shumlib"
+          path: shumlib
       - name: Set up Python ${{ matrix.python-version }}
         uses: actions/setup-python@v5
         with:
@@ -39,12 +46,20 @@ jobs:
           pip install setuptools
           pip install six
           pip install numpy==${{ matrix.numpy-version }}
-      - name: Build python-${{ matrix.python-version }}_numpy-${{ matrix.numpy-version }}
+      - name: Install shumlib
+        working-directory: ./shumlib
+        run: |
+          echo "Compiling shumlib using $(gfortran --version)"
+          make -f ./make/vm-x86-gfortran-gcc.mk check
+      - name: Install Mule with python-${{ matrix.python-version }}_numpy-${{ matrix.numpy-version }}
+        working-directory: ./mule
         run: |
-          ./admin/install_mule.sh ./_build/lib ./_build/bin
-      - name: Test python-${{ matrix.python-version }}_numpy-${{ matrix.numpy-version }}
+          ./admin/install_mule.sh --spiral_lib --packing_lib \
+                                  --shumlib_path $GITHUB_WORKSPACE/shumlib/build/vm-x86-gfortran-gcc \
+                                  ./_build/lib ./_build/bin
+      - name: Test Mule with python-${{ matrix.python-version }}_numpy-${{ matrix.numpy-version }}
+        working-directory: ./mule/_build/lib
         run: |
-          cd _build/lib
           for name in ./*; do
             python -m unittest discover -v ${name##*/}.tests
           done