diff --git a/stubs/Markdown/markdown/blockprocessors.pyi b/stubs/Markdown/markdown/blockprocessors.pyi
index d81ac2939..70919f799 100644
--- a/stubs/Markdown/markdown/blockprocessors.pyi
+++ b/stubs/Markdown/markdown/blockprocessors.pyi
@@ -16,7 +16,7 @@ class BlockProcessor:
     tab_length: int
     def __init__(self, parser: BlockParser) -> None: ...
     def lastChild(self, parent: Element) -> Element | None: ...
-    def detab(self, text: str, length: int | None = ...) -> str: ...
+    def detab(self, text: str, length: int | None = ...) -> tuple[str, str]: ...
     def looseDetab(self, text: str, level: int = ...) -> str: ...
     def test(self, parent: Element, block: str) -> bool: ...
     def run(self, parent: Element, blocks: list[str]) -> bool | None: ...