diff --git a/src/layout/widget.rs b/src/layout/widget.rs
index 0d39ffb..1215980 100644
--- a/src/layout/widget.rs
+++ b/src/layout/widget.rs
@@ -10,7 +10,7 @@ pub trait Widget: Any {
 }
 
 impl Widget for () {
-    fn draw(&mut self, painter: &mut Painter) {}
+    fn draw(&mut self, _: &mut Painter) {}
 }
 
 pub struct WidgetTag;