diff --git a/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.cpp b/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
index 5026c6067e..b08a4420d4 100644
--- a/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.cpp
@@ -31,7 +31,11 @@ namespace Web::HTML {
 
 void FormAssociatedElement::set_form(HTMLFormElement* form)
 {
+    if (m_form)
+        m_form->remove_associated_element({}, form_associated_element_to_html_element());
     m_form = form;
+    if (m_form)
+        m_form->add_associated_element({}, form_associated_element_to_html_element());
 }
 
 }
diff --git a/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.h b/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.h
index 2e7a405adf..6b42a7c16e 100644
--- a/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.h
+++ b/Userland/Libraries/LibWeb/HTML/FormAssociatedElement.h
@@ -39,7 +39,10 @@ public:
     void set_form(HTMLFormElement*);
 
 protected:
-    FormAssociatedElement() { }
+    FormAssociatedElement() = default;
+    virtual ~FormAssociatedElement() = default;
+
+    virtual HTMLElement& form_associated_element_to_html_element() = 0;
 
 private:
     WeakPtr<HTMLFormElement> m_form;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
index 81e4beb453..fc5c699f3a 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
+++ b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2018-2021, Andreas Kling <kling@serenityos.org>
  * All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
@@ -148,4 +148,14 @@ void HTMLFormElement::submit()
     submit_form(this, true);
 }
 
+void HTMLFormElement::add_associated_element(Badge<FormAssociatedElement>, HTMLElement& element)
+{
+    m_associated_elements.append(element);
+}
+
+void HTMLFormElement::remove_associated_element(Badge<FormAssociatedElement>, HTMLElement& element)
+{
+    m_associated_elements.remove_first_matching([&](auto& entry) { return entry.ptr() == &element; });
+}
+
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.h b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.h
index 0368880494..25fa515dff 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLFormElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLFormElement.h
@@ -46,8 +46,13 @@ public:
     // NOTE: This is for the JS bindings. Use submit_form instead.
     void submit();
 
+    void add_associated_element(Badge<FormAssociatedElement>, HTMLElement&);
+    void remove_associated_element(Badge<FormAssociatedElement>, HTMLElement&);
+
 private:
     bool m_firing_submission_events { false };
+
+    Vector<WeakPtr<HTMLElement>> m_associated_elements;
 };
 
 }
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
index ff8cf6d8c7..53b3f51304 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLInputElement.h
@@ -57,9 +57,13 @@ public:
     void did_click_button(Badge<Layout::ButtonBox>);
 
 private:
+    // ^DOM::Node
     virtual void inserted() override;
     virtual void removed_from(Node*) override;
 
+    // ^HTML::FormAssociatedElement
+    virtual HTMLElement& form_associated_element_to_html_element() override { return *this; }
+
     void create_shadow_tree_if_needed();
 
     RefPtr<DOM::Text> m_text_node;
diff --git a/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.h b/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.h
index 1ca77511ff..93bbe6f27f 100644
--- a/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.h
+++ b/Userland/Libraries/LibWeb/HTML/HTMLSelectElement.h
@@ -42,8 +42,12 @@ public:
     virtual ~HTMLSelectElement() override;
 
 private:
+    // ^DOM::Node
     virtual void inserted() override;
     virtual void removed_from(DOM::Node*) override;
+
+    // ^HTML::FormAssociatedElement
+    virtual HTMLElement& form_associated_element_to_html_element() override { return *this; }
 };
 
 }