diff --git a/server.go b/server.go
index a6eeff43..bc363800 100644
--- a/server.go
+++ b/server.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build !appengine
+
 // DNS server implementation.
 
 package dns
diff --git a/server_test.go b/server_test.go
index 1069711d..9749b604 100644
--- a/server_test.go
+++ b/server_test.go
@@ -2,6 +2,8 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
+// +build !appengine
+
 package dns
 
 import (