diff --git a/typer/main.py b/typer/main.py
index 8aa1cf9b3..e17c4b2b8 100644
--- a/typer/main.py
+++ b/typer/main.py
@@ -1044,7 +1044,7 @@ def wrapper(ctx: click.Context, args: List[str], incomplete: Optional[str]) -> A
     return wrapper
 
 
-def run(function: Callable[..., Any]) -> Any:
+def run(function: Callable[..., Any]) -> None:
     app = Typer()
     app.command()(function)
     app()