diff --git a/src/rst_budoux/sphinx.py b/src/rst_budoux/sphinx.py
index 80844d0..25555fa 100644
--- a/src/rst_budoux/sphinx.py
+++ b/src/rst_budoux/sphinx.py
@@ -1 +1,14 @@
 """Implementation as Sphinx-extension."""
+
+from sphinx.application import Sphinx
+
+from . import __version__
+
+
+def setup(app: Sphinx):  # noqa: D103
+    return {
+        "version": __version__,
+        "env_version": 1,
+        "parallel_read_safe": True,
+        "parallel_write_safe": True,
+    }
diff --git a/tests/conftest.py b/tests/conftest.py
new file mode 100644
index 0000000..0592a9e
--- /dev/null
+++ b/tests/conftest.py
@@ -0,0 +1,11 @@
+"""Configuration for pytest."""
+
+import pytest
+from sphinx.testing.path import path
+
+pytest_plugins = "sphinx.testing.fixtures"
+
+
+@pytest.fixture(scope="session")
+def rootdir() -> path:  # noqa: D103
+    return (path(__file__).parent / "doc-targets").abspath()
diff --git a/tests/doc-targets/test-root/conf.py b/tests/doc-targets/test-root/conf.py
new file mode 100644
index 0000000..44965fb
--- /dev/null
+++ b/tests/doc-targets/test-root/conf.py
@@ -0,0 +1,5 @@
+# noqa: D100
+
+extensions = [
+    "rst_budoux.sphinx",
+]
diff --git a/tests/doc-targets/test-root/index.rst b/tests/doc-targets/test-root/index.rst
new file mode 100644
index 0000000..8548719
--- /dev/null
+++ b/tests/doc-targets/test-root/index.rst
@@ -0,0 +1,3 @@
+Test doc for rst-budoux
+=======================
+
diff --git a/tests/test_sphinx.py b/tests/test_sphinx.py
new file mode 100644
index 0000000..8a9baad
--- /dev/null
+++ b/tests/test_sphinx.py
@@ -0,0 +1,10 @@
+"""Standard tests as Sphinx-extension."""
+
+import pytest
+from sphinx.testing.util import SphinxTestApp
+
+
+@pytest.mark.sphinx("html")
+def test__it(app: SphinxTestApp):
+    """Test that it passes with rst-budoux extension."""
+    app.build()