diff --git a/Meta/Lagom/Tools/CodeGenerators/LibWeb/WrapperGenerator.cpp b/Meta/Lagom/Tools/CodeGenerators/LibWeb/WrapperGenerator.cpp
index 35f5172e4c..f0aff61edc 100644
--- a/Meta/Lagom/Tools/CodeGenerators/LibWeb/WrapperGenerator.cpp
+++ b/Meta/Lagom/Tools/CodeGenerators/LibWeb/WrapperGenerator.cpp
@@ -2468,6 +2468,7 @@ using namespace Web::DOM;
 using namespace Web::Geometry;
 using namespace Web::HTML;
 using namespace Web::RequestIdleCallback;
+using namespace Web::XHR;
 
 namespace Web::Bindings {
 
diff --git a/Userland/Libraries/LibWeb/XHR/ProgressEvent.h b/Userland/Libraries/LibWeb/XHR/ProgressEvent.h
index 7cd2ca49d1..a969864e01 100644
--- a/Userland/Libraries/LibWeb/XHR/ProgressEvent.h
+++ b/Userland/Libraries/LibWeb/XHR/ProgressEvent.h
@@ -13,13 +13,23 @@ namespace Web::XHR {
 // FIXME: All the "u32"s should be "u64"s, however LibJS doesn't currently support constructing values with u64,
 //        and the IDL parser doesn't properly parse "unsigned long long".
 
+struct ProgressEventInit : public DOM::EventInit {
+    bool length_computable { false };
+    u32 loaded { 0 };
+    u32 total { 0 };
+};
+
 class ProgressEvent : public DOM::Event {
 public:
     using WrapperType = Bindings::ProgressEventWrapper;
 
-    static NonnullRefPtr<ProgressEvent> create(const FlyString& event_name, u32 transmitted, u32 length)
+    static NonnullRefPtr<ProgressEvent> create(FlyString const& event_name, ProgressEventInit const& event_init)
     {
-        return adopt_ref(*new ProgressEvent(event_name, transmitted, length));
+        return adopt_ref(*new ProgressEvent(event_name, event_init));
+    }
+    static NonnullRefPtr<ProgressEvent> create_with_global_object(Bindings::WindowObject&, FlyString const& event_name, ProgressEventInit const& event_init)
+    {
+        return ProgressEvent::create(event_name, event_init);
     }
 
     virtual ~ProgressEvent() override { }
@@ -29,11 +39,11 @@ public:
     u32 total() const { return m_total; }
 
 protected:
-    ProgressEvent(const FlyString& event_name, u32 transmitted, u32 length)
-        : Event(event_name)
-        , m_length_computable(length != 0)
-        , m_loaded(transmitted)
-        , m_total(length)
+    ProgressEvent(FlyString const& event_name, ProgressEventInit const& event_init)
+        : Event(event_name, event_init)
+        , m_length_computable(event_init.length_computable)
+        , m_loaded(event_init.loaded)
+        , m_total(event_init.total)
     {
     }
 
diff --git a/Userland/Libraries/LibWeb/XHR/ProgressEvent.idl b/Userland/Libraries/LibWeb/XHR/ProgressEvent.idl
index 64e9805ef2..c92731e934 100644
--- a/Userland/Libraries/LibWeb/XHR/ProgressEvent.idl
+++ b/Userland/Libraries/LibWeb/XHR/ProgressEvent.idl
@@ -1,7 +1,15 @@
+#import <DOM/Event.idl>
+
 interface ProgressEvent : Event {
+    constructor(DOMString type, optional ProgressEventInit eventInitDict = {});
 
     readonly attribute boolean lengthComputable;
     readonly attribute unsigned long loaded;
     readonly attribute unsigned long total;
-
+};
+
+dictionary ProgressEventInit : EventInit {
+    boolean lengthComputable = false;
+    unsigned long loaded = 0;
+    unsigned long total = 0;
 };
diff --git a/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp b/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
index 73258099aa..d778e7338a 100644
--- a/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
+++ b/Userland/Libraries/LibWeb/XHR/XMLHttpRequest.cpp
@@ -45,7 +45,11 @@ void XMLHttpRequest::set_ready_state(ReadyState ready_state)
 
 void XMLHttpRequest::fire_progress_event(const String& event_name, u64 transmitted, u64 length)
 {
-    dispatch_event(ProgressEvent::create(event_name, transmitted, length));
+    ProgressEventInit event_init {};
+    event_init.length_computable = true;
+    event_init.loaded = transmitted;
+    event_init.total = length;
+    dispatch_event(ProgressEvent::create(event_name, event_init));
 }
 
 String XMLHttpRequest::response_text() const