diff --git a/src/components/script/dom/bindings/trace.rs b/src/components/script/dom/bindings/trace.rs
index c422a5a0fc4..1cc17474973 100644
--- a/src/components/script/dom/bindings/trace.rs
+++ b/src/components/script/dom/bindings/trace.rs
@@ -167,3 +167,10 @@ impl<T: Reflectable+Encodable<S, E>, S: Encoder<E>, E> Encodable<S, E> for Cell<
         self.get().encode(s)
     }
 }
+
+/// for a field which contains non-POD type contains DOMType
+impl<T: Reflectable+Encodable<S, E>, S: Encoder<E>, E> Encodable<S, E> for RefCell<Vec<JS<T>>> {
+    fn encode(&self, s: &mut S) -> Result<(), E> {
+        self.borrow().encode(s)
+    }
+}