diff --git a/Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp b/Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp
index dd5062f22e..d794c08e25 100644
--- a/Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp
+++ b/Userland/Libraries/LibWeb/HTML/ErrorEvent.cpp
@@ -9,18 +9,18 @@
 
 namespace Web::HTML {
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> ErrorEvent::create(JS::Realm& realm, DeprecatedFlyString const& event_name, ErrorEventInit const& event_init)
+WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> ErrorEvent::create(JS::Realm& realm, FlyString const& event_name, ErrorEventInit const& event_init)
 {
     return MUST_OR_THROW_OOM(realm.heap().allocate<ErrorEvent>(realm, realm, event_name, event_init));
 }
 
-WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> ErrorEvent::construct_impl(JS::Realm& realm, DeprecatedFlyString const& event_name, ErrorEventInit const& event_init)
+WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> ErrorEvent::construct_impl(JS::Realm& realm, FlyString const& event_name, ErrorEventInit const& event_init)
 {
     return create(realm, event_name, event_init);
 }
 
-ErrorEvent::ErrorEvent(JS::Realm& realm, DeprecatedFlyString const& event_name, ErrorEventInit const& event_init)
-    : DOM::Event(realm, event_name)
+ErrorEvent::ErrorEvent(JS::Realm& realm, FlyString const& event_name, ErrorEventInit const& event_init)
+    : DOM::Event(realm, event_name.to_deprecated_fly_string())
     , m_message(event_init.message)
     , m_filename(event_init.filename)
     , m_lineno(event_init.lineno)
diff --git a/Userland/Libraries/LibWeb/HTML/ErrorEvent.h b/Userland/Libraries/LibWeb/HTML/ErrorEvent.h
index 7af56154f3..e67b6cdf92 100644
--- a/Userland/Libraries/LibWeb/HTML/ErrorEvent.h
+++ b/Userland/Libraries/LibWeb/HTML/ErrorEvent.h
@@ -6,14 +6,15 @@
 
 #pragma once
 
+#include <AK/FlyString.h>
 #include <LibWeb/DOM/Event.h>
 
 namespace Web::HTML {
 
 // https://html.spec.whatwg.org/multipage/webappapis.html#erroreventinit
 struct ErrorEventInit : public DOM::EventInit {
-    DeprecatedString message { "" };
-    DeprecatedString filename { "" }; // FIXME: This should be a USVString.
+    String message;
+    String filename; // FIXME: This should be a USVString.
     u32 lineno { 0 };
     u32 colno { 0 };
     JS::Value error { JS::js_null() };
@@ -24,16 +25,16 @@ class ErrorEvent final : public DOM::Event {
     WEB_PLATFORM_OBJECT(ErrorEvent, DOM::Event);
 
 public:
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> create(JS::Realm&, DeprecatedFlyString const& event_name, ErrorEventInit const& event_init = {});
-    static WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> construct_impl(JS::Realm&, DeprecatedFlyString const& event_name, ErrorEventInit const& event_init);
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> create(JS::Realm&, FlyString const& event_name, ErrorEventInit const& event_init = {});
+    static WebIDL::ExceptionOr<JS::NonnullGCPtr<ErrorEvent>> construct_impl(JS::Realm&, FlyString const& event_name, ErrorEventInit const& event_init);
 
     virtual ~ErrorEvent() override;
 
     // https://html.spec.whatwg.org/multipage/webappapis.html#dom-errorevent-message
-    DeprecatedString const& message() const { return m_message; }
+    String const& message() const { return m_message; }
 
     // https://html.spec.whatwg.org/multipage/webappapis.html#dom-errorevent-filename
-    DeprecatedString const& filename() const { return m_filename; }
+    String const& filename() const { return m_filename; }
 
     // https://html.spec.whatwg.org/multipage/webappapis.html#dom-errorevent-lineno
     u32 lineno() const { return m_lineno; }
@@ -45,13 +46,13 @@ public:
     JS::Value error() const { return m_error; }
 
 private:
-    ErrorEvent(JS::Realm&, DeprecatedFlyString const& event_name, ErrorEventInit const& event_init);
+    ErrorEvent(JS::Realm&, FlyString const& event_name, ErrorEventInit const& event_init);
 
     virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
 
-    DeprecatedString m_message { "" };
-    DeprecatedString m_filename { "" }; // FIXME: This should be a USVString.
+    String m_message;
+    String m_filename; // FIXME: This should be a USVString.
     u32 m_lineno { 0 };
     u32 m_colno { 0 };
     JS::Value m_error;
diff --git a/Userland/Libraries/LibWeb/HTML/ErrorEvent.idl b/Userland/Libraries/LibWeb/HTML/ErrorEvent.idl
index 2f8912dffb..b7285b0aac 100644
--- a/Userland/Libraries/LibWeb/HTML/ErrorEvent.idl
+++ b/Userland/Libraries/LibWeb/HTML/ErrorEvent.idl
@@ -1,6 +1,6 @@
 #import <DOM/Event.idl>
 
-[Exposed=(Window,Worker)]
+[Exposed=(Window,Worker), UseNewAKString]
 interface ErrorEvent : Event {
     constructor(DOMString type, optional ErrorEventInit eventInitDict = {});