diff --git a/test/fixedbugs/bug513.go b/test/fixedbugs/bug513.go
index f7604f681c5..459a9c396ac 100644
--- a/test/fixedbugs/bug513.go
+++ b/test/fixedbugs/bug513.go
@@ -1,5 +1,6 @@
 // run -race -gcflags=all=-d=checkptr=0
 // +build linux,amd64 linux,ppc64le darwin,amd64 freebsd,amd64 netbsd,amd64 windows,amd64
+// +build cgo
 
 // Copyright 2021 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style