diff --git a/ztypes_arm64.go b/ztypes_arm64.go
index ff0b8fd..6c29a4b 100644
--- a/ztypes_arm64.go
+++ b/ztypes_arm64.go
@@ -1,6 +1,8 @@
 // Created by cgo -godefs - DO NOT EDIT
 // cgo -godefs types.go
 
+// +build arm64
+
 package pty
 
 type (