diff --git a/bar_option.go b/bar_option.go
index 0b947bf..49ec16a 100644
--- a/bar_option.go
+++ b/bar_option.go
@@ -120,6 +120,7 @@
 	}
 }
 
+// TrimSpace trims bar's edge spaces.
 func TrimSpace() BarOption {
 	return func(s *bState) {
 		s.trimSpace = true