diff --git a/.github/workflows/test-sphinx.yml b/.github/workflows/test-sphinx.yml
new file mode 100644
index 00000000..c44dcc92
--- /dev/null
+++ b/.github/workflows/test-sphinx.yml
@@ -0,0 +1,39 @@
+name: Test
+
+on:
+  push:
+    branches: [ main ]
+  pull_request:
+    branches: [ main ]
+
+jobs:
+  build:
+
+    runs-on: ${{ matrix.os }}
+    env:
+      python-version: '3.10'
+    strategy:
+      matrix:
+        os: [ 'ubuntu-latest' ]
+        python-version: [ '3.10' ]
+        sphinx: [ 'sphinx==5.3.0', 'sphinx==6.2.1', 'sphinx==7.*' ]
+
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+
+    - name: Set up ${{ matrix.sphinx }}
+      run: |
+        python -V
+        python -m pip install --upgrade pip
+        pip install -r requirements.txt
+        pip install -r docs/requirements.txt
+        pip install "${{ matrix.sphinx }}"
+
+    - name: Tests
+      run: |
+        python -m sphinx docs/ build/html -b html -D html_theme=alabaster
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 5de25dff..f98ba38f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -17,10 +17,8 @@ jobs:
         include:
           - os: ubuntu-latest
             python-version: '3.9'
-            tasks: tests
           - os: ubuntu-latest
             python-version: '3.11'
-            tasks: tests
 
     steps:
     - uses: actions/checkout@v4
diff --git a/audbcards/sphinx/__init__.py b/audbcards/sphinx/__init__.py
index 89e4f945..b1b6bdb6 100644
--- a/audbcards/sphinx/__init__.py
+++ b/audbcards/sphinx/__init__.py
@@ -96,7 +96,7 @@ def builder_inited(app: sphinx.application.Sphinx):
             )
             datacard.save(rst_file)
             datasets.append(dataset)
-            out_file = rst_file.replace(app.srcdir, os.path.basename(app.srcdir))
+            out_file = rst_file.replace(str(app.srcdir), os.path.basename(app.srcdir))
             print(f"wrote {out_file}")
 
         # Create datasets overview page