diff --git a/smx509/root_unix.go b/smx509/root_unix.go
index 19b8d44..50f84e9 100644
--- a/smx509/root_unix.go
+++ b/smx509/root_unix.go
@@ -1,4 +1,4 @@
-//go:build aix || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris
+//go:build aix || dragonfly || freebsd || (js && wasm) || linux || netbsd || openbsd || solaris || wasip1
 
 package smx509
 
diff --git a/smx509/root_js.go b/smx509/root_wasm.go
similarity index 53%
rename from smx509/root_js.go
rename to smx509/root_wasm.go
index 2fde43a..8bbad73 100644
--- a/smx509/root_js.go
+++ b/smx509/root_wasm.go
@@ -1,4 +1,8 @@
-//go:build js && wasm
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build wasm
 
 package smx509