diff --git a/Userland/Libraries/LibWeb/DOM/CustomEvent.cpp b/Userland/Libraries/LibWeb/DOM/CustomEvent.cpp
index 0acb715b34..7852fbabc1 100644
--- a/Userland/Libraries/LibWeb/DOM/CustomEvent.cpp
+++ b/Userland/Libraries/LibWeb/DOM/CustomEvent.cpp
@@ -11,12 +11,12 @@
 
 namespace Web::DOM {
 
-CustomEvent* CustomEvent::create(JS::Realm& realm, DeprecatedFlyString const& event_name, CustomEventInit const& event_init)
+WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> CustomEvent::create(JS::Realm& realm, DeprecatedFlyString const& event_name, CustomEventInit const& event_init)
 {
-    return realm.heap().allocate<CustomEvent>(realm, realm, event_name, event_init).release_allocated_value_but_fixme_should_propagate_errors();
+    return MUST_OR_THROW_OOM(realm.heap().allocate<CustomEvent>(realm, realm, event_name, event_init));
 }
 
-CustomEvent* CustomEvent::construct_impl(JS::Realm& realm, DeprecatedFlyString const& event_name, CustomEventInit const& event_init)
+WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> CustomEvent::construct_impl(JS::Realm& realm, DeprecatedFlyString const& event_name, CustomEventInit const& event_init)
 {
     return create(realm, event_name, event_init);
 }
diff --git a/Userland/Libraries/LibWeb/DOM/CustomEvent.h b/Userland/Libraries/LibWeb/DOM/CustomEvent.h
index 3e4f6610cb..84c5bf4306 100644
--- a/Userland/Libraries/LibWeb/DOM/CustomEvent.h
+++ b/Userland/Libraries/LibWeb/DOM/CustomEvent.h
@@ -20,8 +20,8 @@ class CustomEvent : public Event {
     WEB_PLATFORM_OBJECT(CustomEvent, Event);
 
 public:
-    static CustomEvent* create(JS::Realm&, DeprecatedFlyString const& event_name, CustomEventInit const& event_init = {});
-    static CustomEvent* construct_impl(JS::Realm&, DeprecatedFlyString const& event_name, CustomEventInit const& event_init);
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> create(JS::Realm&, DeprecatedFlyString const& event_name, CustomEventInit const& event_init = {});
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<CustomEvent>> construct_impl(JS::Realm&, DeprecatedFlyString const& event_name, CustomEventInit const& event_init);
 
     virtual ~CustomEvent() override;
 
diff --git a/Userland/Libraries/LibWeb/DOM/Document.cpp b/Userland/Libraries/LibWeb/DOM/Document.cpp
index 324778e6a0..f91facea61 100644
--- a/Userland/Libraries/LibWeb/DOM/Document.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Document.cpp
@@ -1276,7 +1276,7 @@ WebIDL::ExceptionOr<JS::NonnullGCPtr<Event>> Document::create_event(DeprecatedSt
     } else if (interface_lowercase == "compositionevent") {
         event = Event::create(realm, ""); // FIXME: Create CompositionEvent
     } else if (interface_lowercase == "customevent") {
-        event = CustomEvent::create(realm, "");
+        event = TRY(CustomEvent::create(realm, ""));
     } else if (interface_lowercase == "devicemotionevent") {
         event = Event::create(realm, ""); // FIXME: Create DeviceMotionEvent
     } else if (interface_lowercase == "deviceorientationevent") {