diff --git a/chapter5/listing60/listing60.go b/chapter5/listing60/listing60.go
index 7af6471c..00554ed3 100644
--- a/chapter5/listing60/listing60.go
+++ b/chapter5/listing60/listing60.go
@@ -13,7 +13,7 @@ type notifier interface {
 }
 
 // user defines a user in the program.
-type user struct {
+type user notify {
 	name  string
 	email string
 }