diff --git a/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp b/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
index 65051540d5..7133108547 100644
--- a/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
+++ b/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.cpp
@@ -2298,21 +2298,22 @@ void HTMLParser::adjust_svg_attributes(HTMLToken& token)
     token.adjust_attribute_name("zoomandpan"_fly_string, "zoomAndPan"_fly_string);
 }
 
+// https://html.spec.whatwg.org/multipage/parsing.html#adjust-foreign-attributes
 void HTMLParser::adjust_foreign_attributes(HTMLToken& token)
 {
-    token.adjust_foreign_attribute("xlink:actuate"_fly_string, "xlink", "actuate"_fly_string, Namespace::XLink);
-    token.adjust_foreign_attribute("xlink:arcrole"_fly_string, "xlink", "arcrole"_fly_string, Namespace::XLink);
-    token.adjust_foreign_attribute("xlink:href"_fly_string, "xlink", "href"_fly_string, Namespace::XLink);
-    token.adjust_foreign_attribute("xlink:role"_fly_string, "xlink", "role"_fly_string, Namespace::XLink);
-    token.adjust_foreign_attribute("xlink:show"_fly_string, "xlink", "show"_fly_string, Namespace::XLink);
-    token.adjust_foreign_attribute("xlink:title"_fly_string, "xlink", "title"_fly_string, Namespace::XLink);
-    token.adjust_foreign_attribute("xlink:type"_fly_string, "xlink", "type"_fly_string, Namespace::XLink);
+    token.adjust_foreign_attribute("xlink:actuate"_fly_string, "xlink"_fly_string, "actuate"_fly_string, Namespace::XLink);
+    token.adjust_foreign_attribute("xlink:arcrole"_fly_string, "xlink"_fly_string, "arcrole"_fly_string, Namespace::XLink);
+    token.adjust_foreign_attribute("xlink:href"_fly_string, "xlink"_fly_string, "href"_fly_string, Namespace::XLink);
+    token.adjust_foreign_attribute("xlink:role"_fly_string, "xlink"_fly_string, "role"_fly_string, Namespace::XLink);
+    token.adjust_foreign_attribute("xlink:show"_fly_string, "xlink"_fly_string, "show"_fly_string, Namespace::XLink);
+    token.adjust_foreign_attribute("xlink:title"_fly_string, "xlink"_fly_string, "title"_fly_string, Namespace::XLink);
+    token.adjust_foreign_attribute("xlink:type"_fly_string, "xlink"_fly_string, "type"_fly_string, Namespace::XLink);
 
-    token.adjust_foreign_attribute("xml:lang"_fly_string, "xml", "lang"_fly_string, Namespace::XML);
-    token.adjust_foreign_attribute("xml:space"_fly_string, "xml", "space"_fly_string, Namespace::XML);
+    token.adjust_foreign_attribute("xml:lang"_fly_string, "xml"_fly_string, "lang"_fly_string, Namespace::XML);
+    token.adjust_foreign_attribute("xml:space"_fly_string, "xml"_fly_string, "space"_fly_string, Namespace::XML);
 
-    token.adjust_foreign_attribute("xmlns"_fly_string, "", "xmlns"_fly_string, Namespace::XMLNS);
-    token.adjust_foreign_attribute("xmlns:xlink"_fly_string, "xmlns", "xlink"_fly_string, Namespace::XMLNS);
+    token.adjust_foreign_attribute("xmlns"_fly_string, {}, "xmlns"_fly_string, Namespace::XMLNS);
+    token.adjust_foreign_attribute("xmlns:xlink"_fly_string, "xmlns"_fly_string, "xlink"_fly_string, Namespace::XMLNS);
 }
 
 void HTMLParser::increment_script_nesting_level()
diff --git a/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.h b/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.h
index 4f691c9dd8..b0229a9e30 100644
--- a/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.h
+++ b/Userland/Libraries/LibWeb/HTML/Parser/HTMLParser.h
@@ -150,7 +150,7 @@ private:
     void adjust_mathml_attributes(HTMLToken&);
     void adjust_svg_tag_names(HTMLToken&);
     void adjust_svg_attributes(HTMLToken&);
-    void adjust_foreign_attributes(HTMLToken&);
+    static void adjust_foreign_attributes(HTMLToken&);
 
     enum AdoptionAgencyAlgorithmOutcome {
         DoNothing,
diff --git a/Userland/Libraries/LibWeb/HTML/Parser/HTMLToken.h b/Userland/Libraries/LibWeb/HTML/Parser/HTMLToken.h
index 9a9d3f1749..33739f7dcc 100644
--- a/Userland/Libraries/LibWeb/HTML/Parser/HTMLToken.h
+++ b/Userland/Libraries/LibWeb/HTML/Parser/HTMLToken.h
@@ -42,9 +42,9 @@ public:
     };
 
     struct Attribute {
-        DeprecatedString prefix;
+        Optional<FlyString> prefix;
         FlyString local_name;
-        FlyString namespace_;
+        Optional<FlyString> namespace_;
         String value;
         Position name_start_position;
         Position value_start_position;
@@ -290,7 +290,7 @@ public:
         });
     }
 
-    void adjust_foreign_attribute(FlyString const& old_name, DeprecatedFlyString const& prefix, FlyString const& local_name, FlyString const& namespace_)
+    void adjust_foreign_attribute(FlyString const& old_name, Optional<FlyString> const& prefix, FlyString const& local_name, Optional<FlyString> const& namespace_)
     {
         VERIFY(is_start_tag() || is_end_tag());
         for_each_attribute([&](Attribute& attribute) {