diff --git a/js/src/xpconnect/src/xpcprivate.h b/js/src/xpconnect/src/xpcprivate.h
index 5dad1589c53..8d2a34e8b66 100644
--- a/js/src/xpconnect/src/xpcprivate.h
+++ b/js/src/xpconnect/src/xpcprivate.h
@@ -1811,6 +1811,8 @@ public:
 
     void
     SetCallback(nsIXPCScriptable* s) {mCallback = s;}
+    void
+    SetCallback(already_AddRefed<nsIXPCScriptable> s) {mCallback = s;}
 
     void
     SetScriptableShared(XPCNativeScriptableShared* shared) {mShared = shared;}
@@ -1859,6 +1861,9 @@ public:
 
     void
     SetCallback(nsIXPCScriptable* callback) {mCallback = callback;}
+    void
+    SetCallback(already_AddRefed<nsIXPCScriptable> callback)
+      {mCallback = callback;}
 
     void
     SetFlags(const XPCNativeScriptableFlags& flags)  {mFlags = flags;}
diff --git a/js/src/xpconnect/src/xpcwrappednative.cpp b/js/src/xpconnect/src/xpcwrappednative.cpp
index 3a352d1428e..82e89084cba 100644
--- a/js/src/xpconnect/src/xpcwrappednative.cpp
+++ b/js/src/xpconnect/src/xpcwrappednative.cpp
@@ -807,7 +807,7 @@ XPCWrappedNative::GatherProtoScriptableCreateInfo(
             if(NS_FAILED(rv))
                 flags = 0;
 
-            sciProto->SetCallback(helper);
+            sciProto->SetCallback(helper.forget());
             sciProto->SetFlags(flags);
         }
     }
@@ -846,7 +846,7 @@ XPCWrappedNative::GatherScriptableCreateInfo(
         if(NS_FAILED(rv))
             flags = 0;
 
-        sciWrapper->SetCallback(helper);
+        sciWrapper->SetCallback(helper.forget());
         sciWrapper->SetFlags(flags);
 
         // A whole series of assertions to catch bad uses of scriptable flags on