diff --git a/third_party/blink/renderer/modules/webcodecs/video_encoder.cc b/third_party/blink/renderer/modules/webcodecs/video_encoder.cc
index 3fc613559ac0c..77c3009bedca8 100644
--- a/third_party/blink/renderer/modules/webcodecs/video_encoder.cc
+++ b/third_party/blink/renderer/modules/webcodecs/video_encoder.cc
@@ -1754,8 +1754,14 @@ ScriptPromise<VideoEncoderSupport> VideoEncoder::isConfigSupported(
       MakeGarbageCollected<ScriptPromiseResolver<VideoEncoderSupport>>(
           script_state);
   auto promise = resolver->Promise();
+  // The HeapBarrierCallback's BindState (via |done_callback_|) may be destroyed
+  // on the media task runner if the worker is terminated before
+  // MojoCodecFactory::Notifier::Notify() fires (BindPostTaskTrampoline drops
+  // the closure inline when PostTask to the dead worker runner fails). Use a
+  // cross-thread handle so |~CrossThreadPersistent| is safe off-thread.
   auto find_any_callback = HeapBarrierCallback<VideoEncoderSupport>(
-      num_callbacks, BindOnce(&FindAnySupported, WrapPersistent(resolver)));
+      num_callbacks, BindOnce(&FindAnySupported,
+                              MakeUnwrappingCrossThreadHandle(resolver)));
 
   if (parsed_config->hw_pref != HardwarePreference::kPreferSoftware ||
       media::MayHaveAndAllowSelectOSSoftwareEncoder(parsed_config->codec)) {