diff --git a/stubs/Markdown/markdown/util.pyi b/stubs/Markdown/markdown/util.pyi
index 878932a70..5d132fe04 100644
--- a/stubs/Markdown/markdown/util.pyi
+++ b/stubs/Markdown/markdown/util.pyi
@@ -17,7 +17,7 @@ RTL_BIDI_RANGES: Any
 
 def deprecated(message: str, stacklevel: int = ...): ...
 def isBlockLevel(tag: object) -> bool: ...
-def parseBoolValue(value, fail_on_errors: bool = ..., preserve_none: bool = ...): ...
+def parseBoolValue(value: object, fail_on_errors: bool = ..., preserve_none: bool = ...) -> bool | None: ...
 def code_escape(text: str) -> str: ...
 
 class AtomicString(str): ...