diff --git a/common/modules/main.jsm b/common/modules/main.jsm
index 0b512220..7d9c8731 100644
--- a/common/modules/main.jsm
+++ b/common/modules/main.jsm
@@ -143,7 +143,6 @@ var Modules = function Modules(window) {
             sandbox.File = jsmodules.File;
             sandbox.Math = jsmodules.Math;
             sandbox.Set = jsmodules.Set;
-            sandbox.__proto__ = proto || modules;
             return sandbox;
         },