diff --git a/stdlib/2and3/warnings.pyi b/stdlib/2and3/warnings.pyi
index 6e8507bfa..67d2b813d 100644
--- a/stdlib/2and3/warnings.pyi
+++ b/stdlib/2and3/warnings.pyi
@@ -13,7 +13,7 @@ def showwarning(message: str, category: Type[Warning], filename: str,
                 lineno: int, file: Optional[TextIO] = ...,
                 line: Optional[str] = ...) -> None: ...
 def formatwarning(message: str, category: Type[Warning], filename: str,
-                  lineno: int, line: Optional[str] = ...) -> None: ...
+                  lineno: int, line: Optional[str] = ...) -> str: ...
 def filterwarnings(action: str, message: str = ...,
                    category: Type[Warning] = ..., module: str = ...,
                    lineno: int = ..., append: bool = ...) -> None: ...