diff --git a/shell/browser/net/proxying_url_loader_factory.cc b/shell/browser/net/proxying_url_loader_factory.cc
index 36ca912156..d8bda0f3ce 100644
--- a/shell/browser/net/proxying_url_loader_factory.cc
+++ b/shell/browser/net/proxying_url_loader_factory.cc
@@ -695,7 +695,7 @@ void ProxyingURLLoaderFactory::CreateLoaderAndStart(
   // Intercept file:// protocol to support asar archives.
   if (request.url.SchemeIsFile()) {
     asar::CreateAsarURLLoader(request, std::move(loader), std::move(client),
-                              nullptr);
+                              new net::HttpResponseHeaders(""));
     return;
   }
 
diff --git a/spec/chromium-spec.js b/spec/chromium-spec.js
index 9226482157..71b9987c05 100644
--- a/spec/chromium-spec.js
+++ b/spec/chromium-spec.js
@@ -194,8 +194,7 @@ describe('chromium feature', () => {
     })
   })
 
-  // FIXME(robo/nornagon): re-enable these once service workers work
-  describe.skip('navigator.serviceWorker', () => {
+  describe('navigator.serviceWorker', () => {
     it('should register for file scheme', (done) => {
       w = new BrowserWindow({
         show: false,