diff --git a/sphinx/ext/autodoc/__init__.py b/sphinx/ext/autodoc/__init__.py
index f2c1ed93782..41051205a33 100644
--- a/sphinx/ext/autodoc/__init__.py
+++ b/sphinx/ext/autodoc/__init__.py
@@ -209,7 +209,7 @@ def process(
         options: dict[str, bool],
         lines: list[str],
     ) -> None:
-        if what_ not in what_unique:
+        if what_unique and what_ not in what_unique:
             return
         del lines[:pre]
         if post: