diff --git a/bar.go b/bar.go
index cc20152..74f197d 100644
--- a/bar.go
+++ b/bar.go
@@ -505,14 +505,15 @@
 
 	if !s.trimSpace && stat.AvailableWidth >= 2 {
 		stat.AvailableWidth -= 2
-		space := func() error {
-			return bufB.WriteByte(' ')
-		}
-		filler := func() error {
-			return s.filler.Fill(bufB, stat)
-		}
-		for _, fn := range []func() error{space, filler, space} {
-			if err := fn(); err != nil {
+		writeFiller := func(buf *bytes.Buffer) error {
+			return s.filler.Fill(buf, stat)
+		}
+		for _, fn := range []func(*bytes.Buffer) error{
+			writeSpace,
+			writeFiller,
+			writeSpace,
+		} {
+			if err := fn(bufB); err != nil {
 				return nil, err
 			}
 		}
@@ -638,3 +639,7 @@
 	}
 	return d
 }
+
+func writeSpace(buf *bytes.Buffer) error {
+	return buf.WriteByte(' ')
+}