--- a/dom/tests/mochitest/fetch/reroute.js
+++ b/dom/tests/mochitest/fetch/reroute.js
@@ -1,3 +1,19 @@
 onfetch = function(e) {
+  if (e.request.url.indexOf("Referer") >= 0) {
+    // Silently rewrite the referrer so the referrer test passes since the
+    // document/worker isn't aware of this service worker.
+    var url = e.request.url.substring(0, e.request.url.indexOf('?'));
+    url += '?headers=' + ({ 'Referer': self.location.href }).toSource();
+
+    e.respondWith(fetch(url, {
+      method: e.request.method,
+      headers: e.request.headers,
+      body: e.request.body,
+      mode: e.request.mode,
+      credentials: e.request.credentials,
+      cache: e.request.cache,
+    }));
+    return;
+  }
   e.respondWith(fetch(e.request));
 };

--- a/dom/workers/ServiceWorkerManager.cpp
+++ b/dom/workers/ServiceWorkerManager.cpp
@@ -3298,32 +3298,34 @@ class FetchEventRunnable : public Worker
   nsAutoPtr<ServiceWorkerClientInfo> mClientInfo;
   nsCString mSpec;
   nsCString mMethod;
   bool mIsReload;
   RequestMode mRequestMode;
   RequestCredentials mRequestCredentials;
   nsContentPolicyType mContentPolicyType;
   nsCOMPtr<nsIInputStream> mUploadStream;
+  nsCString mReferrer;
 public:
   FetchEventRunnable(WorkerPrivate* aWorkerPrivate,
                      nsMainThreadPtrHandle<nsIInterceptedChannel>& aChannel,
                      nsMainThreadPtrHandle<ServiceWorker>& aServiceWorker,
                      nsAutoPtr<ServiceWorkerClientInfo>& aClientInfo,
                      bool aIsReload)
     : WorkerRunnable(aWorkerPrivate, WorkerThreadModifyBusyCount)
     , mInterceptedChannel(aChannel)
     , mServiceWorker(aServiceWorker)
     , mClientInfo(aClientInfo)
     , mIsReload(aIsReload)
     , mRequestMode(RequestMode::No_cors)
     // By default we set it to same-origin since normal HTTP fetches always
     // send credentials to same-origin websites unless explicitly forbidden.
     , mRequestCredentials(RequestCredentials::Same_origin)
     , mContentPolicyType(nsIContentPolicy::TYPE_INVALID)
+    , mReferrer(kFETCH_CLIENT_REFERRER_STR)
   {
     MOZ_ASSERT(aWorkerPrivate);
   }
 
   NS_DECL_ISUPPORTS_INHERITED
 
   NS_IMETHOD
   VisitHeader(const nsACString& aHeader, const nsACString& aValue) override
@@ -3353,16 +3355,25 @@ public:
     NS_ENSURE_SUCCESS(rv, rv);
 
     nsCOMPtr<nsILoadInfo> loadInfo;
     rv = channel->GetLoadInfo(getter_AddRefs(loadInfo));
     NS_ENSURE_SUCCESS(rv, rv);
 
     mContentPolicyType = loadInfo->InternalContentPolicyType();
 
+    nsCOMPtr<nsIURI> referrerURI;
+    rv = NS_GetReferrerFromChannel(channel, getter_AddRefs(referrerURI));
+    // We can't bail on failure since certain non-http channels like JAR
+    // channels are intercepted but don't have referrers.
+    if (NS_SUCCEEDED(rv) && referrerURI) {
+      rv = referrerURI->GetSpec(mReferrer);
+      NS_ENSURE_SUCCESS(rv, rv);
+    }
+
     nsCOMPtr<nsIHttpChannel> httpChannel = do_QueryInterface(channel);
     if (httpChannel) {
       rv = httpChannel->GetRequestMethod(mMethod);
       NS_ENSURE_SUCCESS(rv, rv);
 
       nsCOMPtr<nsIHttpChannelInternal> internalChannel = do_QueryInterface(httpChannel);
       NS_ENSURE_TRUE(internalChannel, NS_ERROR_NOT_AVAILABLE);
 
@@ -3482,16 +3493,17 @@ private:
       return false;
     }
     // For Telemetry, note that this Request object was created by a Fetch event.
     nsRefPtr<InternalRequest> internalReq = request->GetInternalRequest();
     MOZ_ASSERT(internalReq);
     internalReq->SetCreatedByFetchEvent();
 
     internalReq->SetBody(mUploadStream);
+    internalReq->SetReferrer(NS_ConvertUTF8toUTF16(mReferrer));
 
     request->SetContentPolicyType(mContentPolicyType);
 
     RootedDictionary<FetchEventInit> init(aCx);
     init.mRequest.Construct();
     init.mRequest.Value() = request;
     init.mBubbles = false;
     init.mCancelable = true;