diff --git a/Userland/Libraries/LibWeb/DOM/Element.cpp b/Userland/Libraries/LibWeb/DOM/Element.cpp
index b559c0b940..d24d2ea932 100644
--- a/Userland/Libraries/LibWeb/DOM/Element.cpp
+++ b/Userland/Libraries/LibWeb/DOM/Element.cpp
@@ -409,10 +409,15 @@ CSS::CSSStyleDeclaration const* Element::inline_style() const
     return m_inline_style.ptr();
 }
 
-void Element::run_attribute_change_steps(DeprecatedFlyString const& local_name, DeprecatedString const&, DeprecatedString const& value, DeprecatedFlyString const&)
+void Element::add_attribute_change_steps(AttributeChangeSteps steps)
 {
-    // FIXME: Implement the element's attribute change steps:
-    //        https://dom.spec.whatwg.org/#concept-element-attributes-change-ext
+    m_attribute_change_steps.append(move(steps));
+}
+
+void Element::run_attribute_change_steps(DeprecatedFlyString const& local_name, DeprecatedString const& old_value, DeprecatedString const& value, DeprecatedFlyString const& namespace_)
+{
+    for (auto const& attribute_change_steps : m_attribute_change_steps)
+        attribute_change_steps(local_name, old_value, value, namespace_);
 
     // AD-HOC: Run our own internal attribute change handler.
     attribute_changed(local_name, value);
diff --git a/Userland/Libraries/LibWeb/DOM/Element.h b/Userland/Libraries/LibWeb/DOM/Element.h
index b311221d68..385ed16472 100644
--- a/Userland/Libraries/LibWeb/DOM/Element.h
+++ b/Userland/Libraries/LibWeb/DOM/Element.h
@@ -139,6 +139,10 @@ public:
 
     virtual void apply_presentational_hints(CSS::StyleProperties&) const { }
 
+    // https://dom.spec.whatwg.org/#concept-element-attributes-change-ext
+    using AttributeChangeSteps = Function<void(DeprecatedFlyString const& /*local_name*/, DeprecatedString const& /*old_value*/, DeprecatedString const& /*value*/, DeprecatedFlyString const& /*namespace_*/)>;
+
+    void add_attribute_change_steps(AttributeChangeSteps steps);
     void run_attribute_change_steps(DeprecatedFlyString const& local_name, DeprecatedString const& old_value, DeprecatedString const& value, DeprecatedFlyString const& namespace_);
     virtual void attribute_changed(DeprecatedFlyString const& name, DeprecatedString const& value);
 
@@ -379,6 +383,7 @@ private:
     DeprecatedString m_html_uppercased_qualified_name;
 
     JS::GCPtr<NamedNodeMap> m_attributes;
+    Vector<AttributeChangeSteps> m_attribute_change_steps;
     JS::GCPtr<CSS::ElementInlineCSSStyleDeclaration> m_inline_style;
     JS::GCPtr<DOMTokenList> m_class_list;
     JS::GCPtr<ShadowRoot> m_shadow_root;