diff --git a/dom/base/nsDOMClassInfo.cpp b/dom/base/nsDOMClassInfo.cpp
index 207fd953d84f..cdfea4cf2710 100644
--- a/dom/base/nsDOMClassInfo.cpp
+++ b/dom/base/nsDOMClassInfo.cpp
@@ -584,8 +584,7 @@ static nsDOMClassInfoData sClassInfoData[] = {
                            WINDOW_SCRIPTABLE_FLAGS)
 
   NS_DEFINE_CLASSINFO_DATA(Location, nsLocationSH,
-                           (DOM_DEFAULT_SCRIPTABLE_FLAGS &
-                            ~nsIXPCScriptable::ALLOW_PROP_MODS_TO_PROTOTYPE))
+                           DOM_DEFAULT_SCRIPTABLE_FLAGS)
 
   NS_DEFINE_CLASSINFO_DATA(Navigator, nsNavigatorSH,
                            DOM_DEFAULT_SCRIPTABLE_FLAGS |
@@ -6539,10 +6538,7 @@ nsWindowSH::NewResolve(nsIXPConnectWrappedNative *wrapper, JSContext *cx,
 
     JSBool ok = ::JS_DefineUCProperty(cx, obj, ::JS_GetStringChars(str),
                                       ::JS_GetStringLength(str), v, nsnull,
-                                      nsnull,
-                                      JSPROP_PERMANENT |
-                                      JSPROP_READONLY |
-                                      JSPROP_ENUMERATE);
+                                      nsnull, JSPROP_ENUMERATE);
 
     if (!ok) {
       return NS_ERROR_FAILURE;
@@ -8159,10 +8155,7 @@ nsDocumentSH::NewResolve(nsIXPConnectWrappedNative *wrapper, JSContext *cx,
     JSString *str = JSVAL_TO_STRING(id);
     JSBool ok = ::JS_DefineUCProperty(cx, obj, ::JS_GetStringChars(str),
                                       ::JS_GetStringLength(str), v, nsnull,
-                                      nsnull,
-                                      JSPROP_PERMANENT |
-                                      JSPROP_READONLY |
-                                      JSPROP_ENUMERATE);
+                                      nsnull, JSPROP_ENUMERATE);
 
     if (!ok) {
       return NS_ERROR_FAILURE;