1 files changed, 3 insertions, 2 deletions
diff --git a/components/script/dom/mediaquerylist.rs b/components/script/dom/mediaquerylist.rs
index 8b77bc4155b..86f67cdd8a1 100644
--- a/components/script/dom/mediaquerylist.rs
+++ b/components/script/dom/mediaquerylist.rs
@@ -143,8 +143,9 @@ impl WeakMediaQueryListVec {
     }
 }
 
-impl JSTraceable for WeakMediaQueryListVec {
-    fn trace(&self, _: *mut JSTracer) {
+#[allow(unsafe_code)]
+unsafe impl JSTraceable for WeakMediaQueryListVec {
+    unsafe fn trace(&self, _: *mut JSTracer) {
         self.cell.borrow_mut().retain_alive()
     }
 }