diff --git a/container/intsets/popcnt_amd64.go b/container/intsets/popcnt_amd64.go
index 858431ccca..7297f31011 100644
--- a/container/intsets/popcnt_amd64.go
+++ b/container/intsets/popcnt_amd64.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build amd64
+// +build amd64,!appengine
 
 package intsets
 
diff --git a/container/intsets/popcnt_generic.go b/container/intsets/popcnt_generic.go
index 0dc1d7196b..cf1305cfa1 100644
--- a/container/intsets/popcnt_generic.go
+++ b/container/intsets/popcnt_generic.go
@@ -2,7 +2,7 @@
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
-// +build !amd64
+// +build !amd64 appengine
 
 package intsets