diff --git a/cmd/tipgodoc/tip.go b/cmd/tipgodoc/tip.go
index 12a3f4db..cde3857c 100644
--- a/cmd/tipgodoc/tip.go
+++ b/cmd/tipgodoc/tip.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by the Apache 2.0
 // license that can be found in the LICENSE file.
 
+// +build appenginevm
+
 // Command tipgodoc is the beginning of the new tip.golang.org server,
 // serving the latest HEAD straight from the Git oven.
 package main