diff --git a/Userland/Libraries/LibWeb/XHR/FormData.cpp b/Userland/Libraries/LibWeb/XHR/FormData.cpp
index 82014ba4f3..19722689bc 100644
--- a/Userland/Libraries/LibWeb/XHR/FormData.cpp
+++ b/Userland/Libraries/LibWeb/XHR/FormData.cpp
@@ -42,11 +42,18 @@ FormData::FormData(JS::Realm& realm, HashMap<DeprecatedString, Vector<FormDataEn
     : PlatformObject(realm)
     , m_entry_list(move(entry_list))
 {
-    set_prototype(&Bindings::ensure_web_prototype<Bindings::FormDataPrototype>(realm, "FormData"));
 }
 
 FormData::~FormData() = default;
 
+JS::ThrowCompletionOr<void> FormData::initialize(JS::Realm& realm)
+{
+    MUST_OR_THROW_OOM(Base::initialize(realm));
+    set_prototype(&Bindings::ensure_web_prototype<Bindings::FormDataPrototype>(realm, "FormData"));
+
+    return {};
+}
+
 void FormData::visit_edges(Cell::Visitor& visitor)
 {
     Base::visit_edges(visitor);
diff --git a/Userland/Libraries/LibWeb/XHR/FormData.h b/Userland/Libraries/LibWeb/XHR/FormData.h
index 3156de0057..99171309a6 100644
--- a/Userland/Libraries/LibWeb/XHR/FormData.h
+++ b/Userland/Libraries/LibWeb/XHR/FormData.h
@@ -39,6 +39,7 @@ public:
 private:
     explicit FormData(JS::Realm&, HashMap<DeprecatedString, Vector<FormDataEntryValue>> entry_list = {});
 
+    virtual JS::ThrowCompletionOr<void> initialize(JS::Realm&) override;
     virtual void visit_edges(Cell::Visitor&) override;
 
     WebIDL::ExceptionOr<void> append_impl(String const& name, Variant<JS::NonnullGCPtr<FileAPI::Blob>, String> const& value, Optional<String> const& filename = {});