diff --git a/ieproxy_darwin.go b/ieproxy_darwin.go
index 5d53555..9d887c4 100644
--- a/ieproxy_darwin.go
+++ b/ieproxy_darwin.go
@@ -1,3 +1,6 @@
+//go:build darwin && cgo
+// +build darwin,cgo
+
 package ieproxy
 
 /*
diff --git a/ieproxy_windows.go b/ieproxy_windows.go
index 7fd3750..7bf0868 100644
--- a/ieproxy_windows.go
+++ b/ieproxy_windows.go
@@ -1,3 +1,6 @@
+//go:build windows && cgo
+// +build windows,cgo
+
 package ieproxy
 
 import (
diff --git a/pac_darwin.go b/pac_darwin.go
index a8bf90e..71552b2 100644
--- a/pac_darwin.go
+++ b/pac_darwin.go
@@ -1,3 +1,6 @@
+//go:build darwin && cgo
+// +build darwin,cgo
+
 package ieproxy
 
 /*
diff --git a/pac_windows.go b/pac_windows.go
index 6a2ee67..995232f 100644
--- a/pac_windows.go
+++ b/pac_windows.go
@@ -1,3 +1,6 @@
+//go:build windows && cgo
+// +build windows,cgo
+
 package ieproxy
 
 import (