diff --git a/common/modules/storage.jsm b/common/modules/storage.jsm
index 339cafbe..96ce7ed6 100644
--- a/common/modules/storage.jsm
+++ b/common/modules/storage.jsm
@@ -197,7 +197,6 @@ var Storage = Module("Storage", {
         if (!Services.dactylSession)
             Services.dactylSession = Cu.createObjectIn(sessionGlobal);
         this.session = Services.dactylSession;
-        this.windows = WeakMap();
     },
 
     cleanup: function () {