diff --git a/_examples/suppressBar/main.go b/_examples/suppressBar/main.go
index f7d0c3e..b128349 100644
--- a/_examples/suppressBar/main.go
+++ b/_examples/suppressBar/main.go
@@ -81,8 +81,8 @@
 	base mpb.Filler
 }
 
-// implementing mpb.BaseFiller, so bar.SetRefill works
-func (cf *customFiller) BaseFiller() mpb.Filler {
+// implementing mpb.WrapFiller, so bar.SetRefill works
+func (cf *customFiller) Base() mpb.Filler {
 	return cf.base
 }
 
diff --git a/bar.go b/bar.go
index c362da7..1828e67 100644
--- a/bar.go
+++ b/bar.go
@@ -29,11 +29,11 @@
 	f(w, width, stat)
 }
 
-// Wrapper interface.
+// WrapFiller interface.
 // If you're implementing custom Filler by wrapping a built-in one,
 // it is necessary to implement this interface to retain functionality
 // of built-in Filler.
-type Wrapper interface {
+type WrapFiller interface {
 	Base() Filler
 }
 
diff --git a/progress.go b/progress.go
index 1d279fa..c9b72b0 100644
--- a/progress.go
+++ b/progress.go
@@ -389,7 +389,7 @@
 }
 
 func extractBaseFiller(f Filler) Filler {
-	if f, ok := f.(Wrapper); ok {
+	if f, ok := f.(WrapFiller); ok {
 		return extractBaseFiller(f.Base())
 	}
 	return f