diff --git a/.github/workflows/python-app.yml b/.github/workflows/python-app.yml
index 7be4915..8cd93bf 100755
--- a/.github/workflows/python-app.yml
+++ b/.github/workflows/python-app.yml
@@ -10,9 +10,9 @@ on:
     branches: [ main ]
 
 jobs:
-  build:
+  linux:
 
-    runs-on: macos-latest
+    runs-on: ubuntu-latest
 
     steps:
     - uses: actions/checkout@v3
@@ -24,7 +24,6 @@ jobs:
       run: |
         python -m pip install --upgrade pip
         pip install flake8
-        pip3 install git+https://github.com/cnr-isti-vclab/PyMeshLab
         if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
     - name: Lint with flake8
       run: |
@@ -34,4 +33,23 @@ jobs:
         flake8 . --count --exit-zero --max-complexity=10 --statistics
     - name: Run tests
       run: |
-        sh run_tests.sh
+        python -m unittest tests/test_glbutils.py tests/test_glb2mesh.py tests/test_mesh2glb.py
+
+  macos:
+
+    runs-on: macos-latest
+
+    steps:
+    - uses: actions/checkout@v3
+    - name: Set up Python 3.9
+      uses: actions/setup-python@v4
+      with:
+        python-version: 3.9
+    - name: Install dependencies
+      run: |
+        python -m pip install --upgrade pip
+        pip3 install git+https://github.com/cnr-isti-vclab/PyMeshLab
+        if [ -f requirements.txt ]; then pip install -r requirements.txt; fi
+    - name: Run tests
+      run: |
+        python -m unittest tests/test_glbthumb.py