diff --git a/lib/env.js b/lib/env.js
index 22d520203..d9c22feaf 100644
--- a/lib/env.js
+++ b/lib/env.js
@@ -70,7 +70,7 @@ module.exports.create = function (config) {
     const Env = {
         protocol: new URL(httpUnsafeOrigin).protocol,
 
-        fileHost: config.fileHost, // XXX
+        fileHost: config.fileHost || undefined,
         NO_SANDBOX: NO_SANDBOX,
         httpSafePort: httpSafePort,