diff --git a/mouse/mouse.go b/mouse/mouse.go
index 0d3b08a..d21e1d3 100644
--- a/mouse/mouse.go
+++ b/mouse/mouse.go
@@ -15,7 +15,7 @@
 // Package mouse defines known mouse buttons.
 package mouse
 
-// Button represents
+// Button represents a mouse button.
 type Button int
 
 // String implements fmt.Stringer()