diff --git a/netwerk/protocol/http/nsHttpChannel.cpp b/netwerk/protocol/http/nsHttpChannel.cpp
index d7701fc20818..a09300c3c335 100644
--- a/netwerk/protocol/http/nsHttpChannel.cpp
+++ b/netwerk/protocol/http/nsHttpChannel.cpp
@@ -4793,7 +4793,10 @@ nsHttpChannel::AsyncOpen(nsIStreamListener *listener, nsISupports *context)
     MOZ_ASSERT(NS_IsMainThread());
     if (gHttpHandler->PackagedAppsEnabled()) {
         nsAutoCString path;
-        mURI->GetPath(path);
+        nsCOMPtr<nsIURL> url(do_QueryInterface(mURI));
+        if (url) {
+            url->GetFilePath(path);
+        }
         mIsPackagedAppResource = path.Find(PACKAGED_APP_TOKEN) != kNotFound;
     }
 
diff --git a/netwerk/test/unit/test_packaged_app_channel.js b/netwerk/test/unit/test_packaged_app_channel.js
index 7c10cb1ff317..2bffa617dced 100644
--- a/netwerk/test/unit/test_packaged_app_channel.js
+++ b/netwerk/test/unit/test_packaged_app_channel.js
@@ -100,6 +100,12 @@ function contentHandler(metadata, response)
   response.bodyOutputStream.write(body, body.length);
 }
 
+function regularContentHandler(metadata, response)
+{
+  var body = "response";
+  response.bodyOutputStream.write(body, body.length);
+}
+
 var httpserver = null;
 var originalPref = false;
 
@@ -108,6 +114,7 @@ function run_test()
   // setup test
   httpserver = new HttpServer();
   httpserver.registerPathHandler("/package", contentHandler);
+  httpserver.registerPathHandler("/regular", regularContentHandler);
   httpserver.start(-1);
 
   // Enable the feature and save the original pref value
@@ -116,6 +123,7 @@ function run_test()
   do_register_cleanup(reset_pref);
 
   add_test(test_channel);
+  add_test(test_channel_uris);
 
   // run tests
   run_next_test();
@@ -132,6 +140,19 @@ function test_channel() {
   }), null);
 }
 
+function test_channel_uris() {
+  // A `!//` in the query or ref should not be handled as a packaged app resource
+  var channel = make_channel(uri+"/regular?bla!//bla#bla!//bla");
+  channel.asyncOpen(new ChannelListener(check_regular_response, null), null);
+}
+
+function check_regular_response(request, buffer) {
+  request.QueryInterface(Components.interfaces.nsIHttpChannel);
+  do_check_eq(request.responseStatus, 200);
+  do_check_eq(buffer, "response");
+  run_next_test();
+}
+
 function reset_pref() {
   // Set the pref to its original value
   Services.prefs.setBoolPref("network.http.enable-packaged-apps", originalPref);