diff --git a/.github/workflows/test.yaml b/.github/workflows/test.yaml
index 261d50b67..1002696b5 100644
--- a/.github/workflows/test.yaml
+++ b/.github/workflows/test.yaml
@@ -38,23 +38,23 @@ jobs:
   test:
     needs: build-python-package
     name: 'Test ${{ matrix.name }}'
-    runs-on: ${{ matrix.os }}
+    runs-on: ${{ matrix.os }}-latest
     strategy:
       matrix:
         include:
-          - {name: "baseline", os: ubuntu-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
-          - {name: "windows", os: windows-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
-          - {name: "macos", os: macos-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
-          - {name: "python 3.8", os: ubuntu-latest, python-version: "3.8", matrix-backend: numpy, nprocs: 1}
-          - {name: "python 3.9", os: ubuntu-latest, python-version: "3.9", matrix-backend: numpy, nprocs: 1}
-          - {name: "scipy matrix", os: ubuntu-latest, python-version: "3.10", matrix-backend: scipy, nprocs: 1}
-          - {name: "mkl linux", os: ubuntu-latest, python-version: "3.10", matrix-backend: mkl, nprocs: 1}
-          - {name: "mkl linux parallel", os: ubuntu-latest, python-version: "3.10", matrix-backend: mkl, nprocs: 2}
-          - {name: "mkl windows", os: windows-latest, python-version: "3.10", matrix-backend: mkl, nprocs: 1}
-          - {name: "mkl macos", os: macos-latest, python-version: "3.10", matrix-backend: mkl, nprocs: 1}
-          - {name: "parallel", os: ubuntu-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 2}
-          - {name: "numpy 1.17", os: ubuntu-latest, python-version: "3.8", matrix-backend: numpy, nprocs: 1, numpy-version: ==1.17.3}
-          - {name: "tensorial", os: ubuntu-latest, python-version: "3.10", matrix-backend: numpy, nprocs: 1, tensorial: test}
+          - {name: "baseline", os: ubuntu, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
+          - {name: "windows", os: windows, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
+          - {name: "macos", os: macos, python-version: "3.10", matrix-backend: numpy, nprocs: 1}
+          - {name: "python 3.8", os: ubuntu, python-version: "3.8", matrix-backend: numpy, nprocs: 1}
+          - {name: "python 3.9", os: ubuntu, python-version: "3.9", matrix-backend: numpy, nprocs: 1}
+          - {name: "scipy matrix", os: ubuntu, python-version: "3.10", matrix-backend: scipy, nprocs: 1}
+          - {name: "mkl linux", os: ubuntu, python-version: "3.10", matrix-backend: mkl, nprocs: 1}
+          - {name: "mkl linux parallel", os: ubuntu, python-version: "3.10", matrix-backend: mkl, nprocs: 2}
+          - {name: "mkl windows", os: windows, python-version: "3.10", matrix-backend: mkl, nprocs: 1}
+          - {name: "mkl macos", os: macos, python-version: "3.10", matrix-backend: mkl, nprocs: 1}
+          - {name: "parallel", os: ubuntu, python-version: "3.10", matrix-backend: numpy, nprocs: 2}
+          - {name: "numpy 1.17", os: ubuntu, python-version: "3.8", matrix-backend: numpy, nprocs: 1, numpy-version: ==1.17.3}
+          - {name: "tensorial", os: ubuntu, python-version: "3.10", matrix-backend: numpy, nprocs: 1, tensorial: test}
       fail-fast: false
     env:
       _wheel: ${{ needs.build-python-package.outputs.wheel }}
@@ -82,8 +82,11 @@ jobs:
           name: python-package
           path: dist/
       - name: Install Graphviz
-        if: ${{ matrix.os == 'ubuntu-latest' }}
+        if: ${{ matrix.os == 'ubuntu' }}
         run: sudo apt install -y graphviz
+      - name: Install LibGLU
+        if: ${{ matrix.os == 'ubuntu' }}
+        run: sudo apt install -y libglu1
       - name: Install Nutils and dependencies
         id: install
         env:
@@ -92,7 +95,7 @@ jobs:
           python -um pip install --upgrade --upgrade-strategy eager wheel
           python -um pip install --upgrade --upgrade-strategy eager coverage numpy$_numpy_version
           # Install Nutils from `dist` dir created in job `build-python-package`.
-          python -um pip install "$_wheel[import_gmsh,export_mpl]"
+          python -um pip install "$_wheel[import_gmsh,export_mpl,cs]"
       - name: Install Scipy
         if: ${{ matrix.matrix-backend == 'scipy' }}
         run: python -um pip install --upgrade scipy
@@ -135,12 +138,15 @@ jobs:
         with:
           name: python-package
           path: dist/
+      - name: Install LibGLU
+        if: ${{ matrix.os == 'ubuntu' }}
+        run: sudo apt install -y libglu1
       - name: Install Nutils and dependencies
         id: install
         run: |
           python -um pip install --upgrade --upgrade-strategy eager wheel
           # Install Nutils from `dist` dir created in job `build-python-package`.
-          python -um pip install "$_wheel[matrix_scipy,export_mpl]"
+          python -um pip install "$_wheel[matrix_scipy,export_mpl,cs]"
       - name: Test
         run: python -um unittest discover -b -q -t . -s examples
   test-sphinx:
diff --git a/pyproject.toml b/pyproject.toml
index 2e039fdea..5bb659408 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -26,7 +26,8 @@ docs = ["Sphinx>=1.8"]
 export_mpl = ["matplotlib>=1.3", "pillow>2.6"]
 matrix_mkl = ["mkl"]
 matrix_scipy = ["scipy>=0.13"]
-import_gmsh = ["meshio"]
+import_gmsh = ["meshio>=5"]
+cs = ["gmsh>=4", "meshio>=5"]
 
 [build-system]
 requires = ["flit_core >=3.2,<4"]