diff --git a/javascript/firefox-driver/extension/components/httpd.js b/javascript/firefox-driver/extension/components/httpd.js
index 7de6edb1bb972..c8abee2db0167 100644
--- a/javascript/firefox-driver/extension/components/httpd.js
+++ b/javascript/firefox-driver/extension/components/httpd.js
@@ -836,7 +836,7 @@ nsHttpServer.prototype =
     // Bug 508125: Add a GC here else we'll use gigabytes of memory running
     // mochitests. We can't rely on xpcshell doing an automated GC, as that
     // would interfere with testing GC stuff...
-    Components.utils.forceGC();
+    gc()
   },
 
   /**