diff --git a/Libraries/LibWeb/DOM/Document.cpp b/Libraries/LibWeb/DOM/Document.cpp
index dc79aa6b6c4..f9c535dec8c 100644
--- a/Libraries/LibWeb/DOM/Document.cpp
+++ b/Libraries/LibWeb/DOM/Document.cpp
@@ -1158,6 +1158,33 @@ GC::Ptr<HTML::HTMLBaseElement> Document::first_base_element_with_target_in_tree_
     return m_first_base_element_with_target_in_tree_order;
 }
 
+// https://html.spec.whatwg.org/multipage/urls-and-fetching.html#respond-to-base-url-changes
+void Document::respond_to_base_url_changes()
+{
+    // To respond to base URL changes for a Document document:
+
+    // 1. The user agent should update any user interface elements which are displaying affected URLs, or data derived
+    //    from such URLs, to the user. Examples of such user interface elements would be a status bar that displays a
+    //    hyperlink's url, or some user interface which displays the URL specified by a q, blockquote, ins, or del
+    //    element's cite attribute.
+    // FIXME: Update those UI elements.
+
+    // 2. Ensure that the CSS :link/:visited/etc. pseudo-classes are updated appropriately.
+    invalidate_style(StyleInvalidationReason::BaseURLChanged);
+}
+
+// https://html.spec.whatwg.org/multipage/urls-and-fetching.html#set-the-url
+void Document::set_url(URL::URL const& url)
+{
+    // To set the URL for a Document document to a URL record url:
+
+    // 1. Set document's URL to url.
+    m_url = url;
+
+    // 2. Respond to base URL changes given document.
+    respond_to_base_url_changes();
+}
+
 // https://html.spec.whatwg.org/multipage/urls-and-fetching.html#fallback-base-url
 URL::URL Document::fallback_base_url() const
 {
@@ -1181,12 +1208,12 @@ URL::URL Document::fallback_base_url() const
 // https://html.spec.whatwg.org/multipage/urls-and-fetching.html#document-base-url
 URL::URL Document::base_url() const
 {
-    // 1. If there is no base element that has an href attribute in the Document, then return the Document's fallback base URL.
+    // 1. If document has no descendant base element that has an href attribute, then return document's fallback base URL.
     auto base_element = first_base_element_with_href_in_tree_order();
     if (!base_element)
         return fallback_base_url();
 
-    // 2. Otherwise, return the frozen base URL of the first base element in the Document that has an href attribute, in tree order.
+    // 2. Otherwise, return the frozen base URL of the first base element in document that has an href attribute, in tree order.
     return base_element->frozen_base_url();
 }
 
diff --git a/Libraries/LibWeb/DOM/Document.h b/Libraries/LibWeb/DOM/Document.h
index 127c72b28d4..ad6a8b17016 100644
--- a/Libraries/LibWeb/DOM/Document.h
+++ b/Libraries/LibWeb/DOM/Document.h
@@ -222,7 +222,7 @@ public:
     String referrer() const;
     void set_referrer(String);
 
-    void set_url(const URL::URL& url) { m_url = url; }
+    void set_url(URL::URL const& url);
     URL::URL url() const { return m_url; }
     URL::URL fallback_base_url() const;
     URL::URL base_url() const;
@@ -230,6 +230,7 @@ public:
     void update_base_element(Badge<HTML::HTMLBaseElement>);
     GC::Ptr<HTML::HTMLBaseElement> first_base_element_with_href_in_tree_order() const;
     GC::Ptr<HTML::HTMLBaseElement> first_base_element_with_target_in_tree_order() const;
+    void respond_to_base_url_changes();
 
     String url_string() const { return m_url.to_string(); }
     String document_uri() const { return url_string(); }
diff --git a/Libraries/LibWeb/DOM/Node.h b/Libraries/LibWeb/DOM/Node.h
index 1952a9baf05..af9e8730b54 100644
--- a/Libraries/LibWeb/DOM/Node.h
+++ b/Libraries/LibWeb/DOM/Node.h
@@ -50,6 +50,7 @@ enum class ShouldComputeRole {
 
 #define ENUMERATE_STYLE_INVALIDATION_REASONS(X)     \
     X(AdoptedStyleSheetsList)                       \
+    X(BaseURLChanged)                               \
     X(CSSFontLoaded)                                \
     X(CSSImportRule)                                \
     X(CSSStylePropertiesRemoveProperty)             \
diff --git a/Libraries/LibWeb/HTML/HTMLBaseElement.cpp b/Libraries/LibWeb/HTML/HTMLBaseElement.cpp
index cf6673f083e..a6e7bf63e65 100644
--- a/Libraries/LibWeb/HTML/HTMLBaseElement.cpp
+++ b/Libraries/LibWeb/HTML/HTMLBaseElement.cpp
@@ -95,6 +95,9 @@ void HTMLBaseElement::set_the_frozen_base_url()
 
     // 4. Set element's frozen base URL to urlRecord.
     m_frozen_base_url = url_record.release_value();
+
+    // 5. Respond to base URL changes given document.
+    document.respond_to_base_url_changes();
 }
 
 // https://html.spec.whatwg.org/multipage/semantics.html#dom-base-href
diff --git a/Libraries/LibWeb/HTML/Navigable.cpp b/Libraries/LibWeb/HTML/Navigable.cpp
index 68b80ada239..c2d5e634019 100644
--- a/Libraries/LibWeb/HTML/Navigable.cpp
+++ b/Libraries/LibWeb/HTML/Navigable.cpp
@@ -2286,7 +2286,7 @@ void perform_url_and_history_update_steps(DOM::Document& document, URL::URL new_
     if (serialized_data.has_value())
         document.restore_the_history_object_state(new_entry);
 
-    // 8. Set document's URL to newURL.
+    // 8. Set the URL given document to newURL.
     document.set_url(new_url);
 
     // 9. Set document's latest entry to newEntry.