diff --git a/v3/pkg/w32/window.go b/v3/pkg/w32/window.go
index 3f626228b..fec225cfe 100644
--- a/v3/pkg/w32/window.go
+++ b/v3/pkg/w32/window.go
@@ -1,3 +1,4 @@
+//go:build windows
 package w32
 
 import (