diff --git a/src/mkdocstrings/extension.py b/src/mkdocstrings/extension.py
index 02b94fc9..5b8848ab 100644
--- a/src/mkdocstrings/extension.py
+++ b/src/mkdocstrings/extension.py
@@ -127,17 +127,18 @@ def run(self, parent: Element, blocks: MutableSequence[str]) -> None:
             el.extend(headings)
 
             page = self._autorefs.current_page
-            for heading in headings:
-                anchor = heading.attrib["id"]  # noqa: WPS440
-                self._autorefs.register_anchor(page, anchor)  # noqa: WPS441
-
-                if "data-role" in heading.attrib:
-                    self._handlers.inventory.register(
-                        name=anchor,  # noqa: WPS441
-                        domain=handler.domain,
-                        role=heading.attrib["data-role"],
-                        uri=f"{page}#{anchor}",  # noqa: WPS441
-                    )
+            if page:
+                for heading in headings:
+                    anchor = heading.attrib["id"]  # noqa: WPS440
+                    self._autorefs.register_anchor(page, anchor)  # noqa: WPS441
+
+                    if "data-role" in heading.attrib:
+                        self._handlers.inventory.register(
+                            name=anchor,  # noqa: WPS441
+                            domain=handler.domain,
+                            role=heading.attrib["data-role"],
+                            uri=f"{page}#{anchor}",  # noqa: WPS441
+                        )
 
             parent.append(el)
 
diff --git a/src/mkdocstrings/loggers.py b/src/mkdocstrings/loggers.py
index d2722616..f75d31d2 100644
--- a/src/mkdocstrings/loggers.py
+++ b/src/mkdocstrings/loggers.py
@@ -11,7 +11,7 @@
 try:
     from jinja2 import pass_context
 except ImportError:  # TODO: remove once Jinja2 < 3.1 is dropped
-    from jinja2 import contextfunction as pass_context  # noqa: WPS440
+    from jinja2 import contextfunction as pass_context  # type: ignore  # noqa: WPS440
 
 try:
     import mkdocstrings_handlers
diff --git a/src/mkdocstrings/plugin.py b/src/mkdocstrings/plugin.py
index 7ec0b85d..2c791774 100644
--- a/src/mkdocstrings/plugin.py
+++ b/src/mkdocstrings/plugin.py
@@ -111,7 +111,9 @@ def handlers(self) -> Handlers:
         return self._handlers
 
     # TODO: remove once watch feature is removed
-    def on_serve(self, server: LiveReloadServer, builder: Callable, **kwargs: Any):  # noqa: W0613 (unused arguments)
+    def on_serve(
+        self, server: LiveReloadServer, config: Config, builder: Callable, *args: Any, **kwargs: Any
+    ) -> None:  # noqa: W0613 (unused arguments)
         """Watch directories.
 
         Hook for the [`on_serve` event](https://www.mkdocs.org/user-guide/plugins/#on_serve).
@@ -121,7 +123,9 @@ def on_serve(self, server: LiveReloadServer, builder: Callable, **kwargs: Any):
 
         Arguments:
             server: The `livereload` server instance.
+            config: The MkDocs config object (unused).
             builder: The function to build the site.
+            *args: Additional arguments passed by MkDocs.
             **kwargs: Additional arguments passed by MkDocs.
         """
         if self.config["watch"]:
@@ -216,7 +220,7 @@ def inventory_enabled(self) -> bool:
             inventory_enabled = any(handler.enable_inventory for handler in self.handlers.seen_handlers)
         return inventory_enabled
 
-    def on_env(self, env, config: Config, **kwargs):
+    def on_env(self, env, config: Config, *args, **kwargs) -> None:
         """Extra actions that need to happen after all Markdown rendering and before HTML rendering.
 
         Hook for the [`on_env` event](https://www.mkdocs.org/user-guide/plugins/#on_env).