diff --git a/components/script/dom/bindings/cell.rs b/components/script/dom/bindings/cell.rs
index f250e818412..81085256821 100644
--- a/components/script/dom/bindings/cell.rs
+++ b/components/script/dom/bindings/cell.rs
@@ -52,7 +52,7 @@ impl<T> DOMRefCell<T> {
     ///
     /// For safety checks in debug builds only.
     pub fn is_mutably_borrowed(&self) -> bool {
-        self.value.try_borrow().is_some()
+        self.value.borrow_state() == BorrowState::Writing
     }
 
     /// Attempts to immutably borrow the wrapped value.