diff --git a/components/script/dom/htmlmediaelement.rs b/components/script/dom/htmlmediaelement.rs
index 9a4c394649a..7a94768c13a 100644
--- a/components/script/dom/htmlmediaelement.rs
+++ b/components/script/dom/htmlmediaelement.rs
@@ -801,6 +801,8 @@ impl PauseIfNotInDocumentTask {
 }
 
 impl Runnable for PauseIfNotInDocumentTask {
+    fn name(&self) -> &'static str { "PauseIfNotInDocumentTask" }
+
     fn handler(self: Box<PauseIfNotInDocumentTask>) {
         let elem = self.elem.root();
         if !elem.upcast::<Node>().is_in_doc() {