diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
index b5a4753dec..d7f2166b39 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/BindingsGenerator/IDLGenerators.cpp
@@ -27,6 +27,7 @@ static bool is_platform_object(Type const& type)
     static constexpr Array types = {
         "AbortSignal"sv,
         "Attr"sv,
+        "AudioTrack"sv,
         "Blob"sv,
         "CanvasGradient"sv,
         "CanvasPattern"sv,
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
index ff863fa1b0..b132e15330 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLMediaElement.cpp
@@ -1020,9 +1020,9 @@ WebIDL::ExceptionOr<void> HTMLMediaElement::process_media_data(Function<void(Str
 
         // 7. Fire an event named addtrack at this VideoTrackList object, using TrackEvent, with the track attribute initialized to the new VideoTrack object.
         TrackEventInit event_init {};
-        event_init.track = video_track;
+        event_init.track = JS::make_handle(video_track);
 
-        auto event = TRY(TrackEvent::create(realm, HTML::EventNames::addtrack, event_init));
+        auto event = TRY(TrackEvent::create(realm, HTML::EventNames::addtrack, move(event_init)));
         m_video_tracks->dispatch_event(event);
     }
 
diff --git a/Userland/Libraries/LibWeb/HTML/TrackEvent.cpp b/Userland/Libraries/LibWeb/HTML/TrackEvent.cpp
index 22a3a18837..4402fe1249 100644
--- a/Userland/Libraries/LibWeb/HTML/TrackEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/TrackEvent.cpp
@@ -10,19 +10,19 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> TrackEvent::create(JS::Realm& realm, FlyString const& event_name, TrackEventInit const& event_init)
+WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> TrackEvent::create(JS::Realm& realm, FlyString const& event_name, TrackEventInit event_init)
 {
-    return MUST_OR_THROW_OOM(realm.heap().allocate<TrackEvent>(realm, realm, event_name, event_init));
+    return MUST_OR_THROW_OOM(realm.heap().allocate<TrackEvent>(realm, realm, event_name, move(event_init)));
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> TrackEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, TrackEventInit const& event_init)
+WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> TrackEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, TrackEventInit event_init)
 {
-    return create(realm, event_name, event_init);
+    return create(realm, event_name, move(event_init));
 }
 
-TrackEvent::TrackEvent(JS::Realm& realm, FlyString const& event_name, TrackEventInit const& event_init)
+TrackEvent::TrackEvent(JS::Realm& realm, FlyString const& event_name, TrackEventInit event_init)
     : DOM::Event(realm, event_name, event_init)
-    , m_track(event_init.track)
+    , m_track(move(event_init.track))
 {
 }
 
@@ -34,4 +34,15 @@ JS::ThrowCompletionOr<void> TrackEvent::initialize(JS::Realm& realm)
     return {};
 }
 
+Variant<Empty, JS::Handle<VideoTrack>, JS::Handle<AudioTrack>> TrackEvent::track() const
+{
+    // FIXME: This is a bit awkward. When creating a nullable union, our IDL generator creates a type of
+    //        Optional<Variant<...>>, using an empty Optional to represent null. But when retrieving the
+    //        attribute, it expects a type of Variant<Empty, ...>, using Empty to represent null.
+    if (!m_track.has_value())
+        return Empty {};
+
+    return *m_track;
+}
+
 }
diff --git a/Userland/Libraries/LibWeb/HTML/TrackEvent.h b/Userland/Libraries/LibWeb/HTML/TrackEvent.h
index b0c0a85864..16ae83a5db 100644
--- a/Userland/Libraries/LibWeb/HTML/TrackEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/TrackEvent.h
@@ -7,30 +7,34 @@
 #pragma once
 
 #include <AK/FlyString.h>
+#include <AK/Optional.h>
+#include <AK/Variant.h>
+#include <LibJS/Heap/Handle.h>
 #include <LibWeb/DOM/Event.h>
 
 namespace Web::HTML {
 
 struct TrackEventInit : public DOM::EventInit {
-    JS::GCPtr<VideoTrack> track;
+    using TrackType = Optional<Variant<JS::Handle<VideoTrack>, JS::Handle<AudioTrack>>>;
+    TrackType track;
 };
 
 class TrackEvent : public DOM::Event {
     WEB_PLATFORM_OBJECT(TrackEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> create(JS::Realm&, FlyString const& event_name, TrackEventInit const& event_init = {});
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> construct_impl(JS::Realm&, FlyString const& event_name, TrackEventInit const& event_init);
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> create(JS::Realm&, FlyString const& event_name, TrackEventInit event_init = {});
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<TrackEvent>> construct_impl(JS::Realm&, FlyString const& event_name, TrackEventInit event_init);
 
     // https://html.spec.whatwg.org/multipage/media.html#dom-trackevent-track
-    JS::GCPtr<VideoTrack> track() const { return m_track; }
+    Variant<Empty, JS::Handle<VideoTrack>, JS::Handle<AudioTrack>> track() const;
 
 private:
-    TrackEvent(JS::Realm&, FlyString const& event_name, TrackEventInit const& event_init);
+    TrackEvent(JS::Realm&, FlyString const& event_name, TrackEventInit event_init);
 
     virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
 
-    JS::GCPtr<VideoTrack> m_track;
+    TrackEventInit::TrackType m_track;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/HTML/TrackEvent.idl b/Userland/Libraries/LibWeb/HTML/TrackEvent.idl
index 3696e6a0de..41d45b2628 100644
--- a/Userland/Libraries/LibWeb/HTML/TrackEvent.idl
+++ b/Userland/Libraries/LibWeb/HTML/TrackEvent.idl
@@ -1,4 +1,5 @@
 #import <DOM/Event.idl>
+#import <HTML/AudioTrack.idl>
 #import <HTML/VideoTrack.idl>
 
 // https://html.spec.whatwg.org/multipage/media.html#trackevent
@@ -7,10 +8,10 @@ interface TrackEvent : Event {
     constructor(DOMString type, optional TrackEventInit eventInitDict = {});
 
     // FIXME: Should be: (VideoTrack or AudioTrack or TextTrack)?
-    readonly attribute VideoTrack? track;
+    readonly attribute (VideoTrack or AudioTrack)? track;
 };
 
 dictionary TrackEventInit : EventInit {
     // FIXME: Should be: (VideoTrack or AudioTrack or TextTrack)?
-    VideoTrack? track = null;
+    (VideoTrack or AudioTrack)? track = null;
 };