diff --git a/mesop/components/box/box.py b/mesop/components/box/box.py
index b47f8eb0a..58ceeece0 100644
--- a/mesop/components/box/box.py
+++ b/mesop/components/box/box.py
@@ -13,7 +13,7 @@
 def box(
   *,
   style: str = "",
-  on_click: Callable[[ClickEvent], Any] | Callable[[], Any] | None = None,
+  on_click: Callable[[ClickEvent], Any] | None = None,
   key: str | None = None,
 ) -> Any:
   """Creates a box component.
diff --git a/mesop/components/button/button.py b/mesop/components/button/button.py
index edf6f8397..b5eff1d63 100644
--- a/mesop/components/button/button.py
+++ b/mesop/components/button/button.py
@@ -12,7 +12,7 @@
 @validate
 def button(
   *,
-  on_click: Callable[[ClickEvent], Any] | Callable[[], Any] | None = None,
+  on_click: Callable[[ClickEvent], Any] | None = None,
   variant: Literal["raised", "flat", "stroked", "icon"] | None = None,
   color: str = "",
   disable_ripple: bool = False,