diff --git a/bar_option.go b/bar_option.go
index 71ce452..d3cb3e2 100644
--- a/bar_option.go
+++ b/bar_option.go
@@ -88,10 +88,10 @@
 
 // BarFillerMiddleware provides a way to augment the underlying BarFiller.
 func BarFillerMiddleware(middle func(BarFiller) BarFiller) BarOption {
-	return func(s *bState) {
-		if middle == nil {
-			return
-		}
+	if middle == nil {
+		return nil
+	}
+	return func(s *bState) {
 		s.filler = middle(s.filler)
 	}
 }