diff --git a/tests/test_shared_sources.py b/tests/test_shared_sources.py
index 0deeec12..1b0d5506 100644
--- a/tests/test_shared_sources.py
+++ b/tests/test_shared_sources.py
@@ -14,6 +14,9 @@ def fixture(self, root: Path) -> None:
         (root / "developer_manual/integration").mkdir(parents=True)
         (root / "developer_manual/integration/index.rst").write_text("Architecture")
         (root / "developer_manual/integration/new-guide.rst").write_text("New guide")
+        (root / "developer_manual/integration/_native-webhooks.inc").write_text(
+            "Development completion event"
+        )
         (root / "developer_manual/api").mkdir()
         (root / "developer_manual/api/openapi.rst").write_text("OpenAPI")
         (root / "developer_manual/html").mkdir()
@@ -44,6 +47,8 @@ def test_new_rst_is_shared_without_editing_python(self):
                 (stable / "integration/_native-webhooks.inc").read_text(), "Only polling")
             self.assertEqual(
                 (upcoming / "integration/_native-webhooks.inc").read_text(), "Native event")
+            self.assertEqual((dev / "integration/_native-webhooks.inc").read_text(),
+                             "Development completion event")
             self.assertFalse((stable / "integration/source-only.rst").exists())
 
     def test_unlisted_development_section_is_not_leaked(self):
diff --git a/versioning/build.py b/versioning/build.py
index 27683bce..b51ee70c 100644
--- a/versioning/build.py
+++ b/versioning/build.py
@@ -49,11 +49,11 @@ def source_tree(stage: Path, slug: str, manual: str) -> Path:
     if slug == "main":
         shutil.copytree(ROOT / manual, target)
     else:
-        shutil.copytree(ROOT / "versioned/base" / manual, target)
-        # Contributors declare version-safe sections in versioned/shared.json.
-        # Copy them before release overlays; no Python change for new RST pages.
+        target.mkdir(parents=True, exist_ok=True)
+        # Stable base documentation takes precedence over shared sections.
         for relative, source in shared_sources(manual):
             shutil.copytree(source, target / relative, dirs_exist_ok=True)
+        shutil.copytree(ROOT / "versioned/base" / manual, target, dirs_exist_ok=True)
         overlay = ROOT / "versioned" / slug / manual
         if overlay.exists():
             shutil.copytree(overlay, target, dirs_exist_ok=True)