diff --git a/malloc_heap.go b/malloc_heap.go
index 810d460..b80861b 100644
--- a/malloc_heap.go
+++ b/malloc_heap.go
@@ -1,5 +1,5 @@
-//go:build appengine || windows
-// +build appengine windows
+//go:build appengine || windows || js
+// +build appengine windows js
 
 package fastcache
 
diff --git a/malloc_mmap.go b/malloc_mmap.go
index e24d578..3aa107f 100644
--- a/malloc_mmap.go
+++ b/malloc_mmap.go
@@ -1,5 +1,5 @@
-//go:build !appengine && !windows
-// +build !appengine,!windows
+//go:build !appengine && !windows && !js
+// +build !appengine,!windows,!js
 
 package fastcache