diff --git a/src/go/types/api.go b/src/go/types/api.go
index d2522594e7..697c609c87 100644
--- a/src/go/types/api.go
+++ b/src/go/types/api.go
@@ -22,6 +22,8 @@
 // and checks for compliance with the language specification.
 // Use Info.Types[expr].Type for the results of type inference.
 //
+// For a tutorial, see https://golang.org/s/types-tutorial.
+//
 package types // import "go/types"
 
 import (