diff --git a/Libraries/LibWeb/CSS/CSSStyleValue.cpp b/Libraries/LibWeb/CSS/CSSStyleValue.cpp
index 7865d3ae599..846d838e5d5 100644
--- a/Libraries/LibWeb/CSS/CSSStyleValue.cpp
+++ b/Libraries/LibWeb/CSS/CSSStyleValue.cpp
@@ -13,12 +13,12 @@ namespace Web::CSS {
 
 GC_DEFINE_ALLOCATOR(CSSStyleValue);
 
-GC::Ref<CSSStyleValue> CSSStyleValue::create(JS::Realm& realm, Optional<String> associated_property, Optional<String> constructed_from_string)
+GC::Ref<CSSStyleValue> CSSStyleValue::create(JS::Realm& realm, String associated_property, String constructed_from_string)
 {
     return realm.create<CSSStyleValue>(realm, move(associated_property), move(constructed_from_string));
 }
 
-CSSStyleValue::CSSStyleValue(JS::Realm& realm, Optional<String> associated_property, Optional<String> constructed_from_string)
+CSSStyleValue::CSSStyleValue(JS::Realm& realm, String associated_property, String constructed_from_string)
     : PlatformObject(realm)
     , m_associated_property(move(associated_property))
     , m_constructed_from_string(move(constructed_from_string))
diff --git a/Libraries/LibWeb/CSS/CSSStyleValue.h b/Libraries/LibWeb/CSS/CSSStyleValue.h
index bc2dbb5ad63..eb18a13297b 100644
--- a/Libraries/LibWeb/CSS/CSSStyleValue.h
+++ b/Libraries/LibWeb/CSS/CSSStyleValue.h
@@ -16,14 +16,14 @@ class CSSStyleValue : public Bindings::PlatformObject {
     GC_DECLARE_ALLOCATOR(CSSStyleValue);
 
 public:
-    [[nodiscard]] static GC::Ref<CSSStyleValue> create(JS::Realm&, Optional<String> associated_property = {}, Optional<String> constructed_from_string = {});
+    [[nodiscard]] static GC::Ref<CSSStyleValue> create(JS::Realm&, String associated_property, String constructed_from_string);
 
     virtual ~CSSStyleValue() override = default;
 
     virtual String to_string() const;
 
 private:
-    explicit CSSStyleValue(JS::Realm&, Optional<String> associated_property = {}, Optional<String> constructed_from_string = {});
+    explicit CSSStyleValue(JS::Realm&, String associated_property, String constructed_from_string);
 
     virtual void initialize(JS::Realm&) override;
 
diff --git a/Libraries/LibWeb/CSS/StyleValues/StyleValue.cpp b/Libraries/LibWeb/CSS/StyleValues/StyleValue.cpp
index 02f3295914f..d0bb26a0577 100644
--- a/Libraries/LibWeb/CSS/StyleValues/StyleValue.cpp
+++ b/Libraries/LibWeb/CSS/StyleValues/StyleValue.cpp
@@ -10,6 +10,7 @@
 #include <LibGfx/Font/Font.h>
 #include <LibGfx/Font/FontStyleMapping.h>
 #include <LibGfx/Font/FontWeight.h>
+#include <LibWeb/CSS/CSSStyleValue.h>
 #include <LibWeb/CSS/Parser/Parser.h>
 #include <LibWeb/CSS/StyleValues/AbstractImageStyleValue.h>
 #include <LibWeb/CSS/StyleValues/AnchorSizeStyleValue.h>
@@ -142,6 +143,13 @@ Vector<Parser::ComponentValue> StyleValue::tokenize() const
     return Parser::Parser::create(Parser::ParsingParams {}, to_string(SerializationMode::Normal)).parse_as_list_of_component_values();
 }
 
+// https://drafts.css-houdini.org/css-typed-om-1/#reify-as-a-cssstylevalue
+GC::Ref<CSSStyleValue> StyleValue::reify(JS::Realm& realm, String const& associated_property) const
+{
+    // 1. Return a new CSSStyleValue object representing value whose [[associatedProperty]] internal slot is set to property.
+    return CSSStyleValue::create(realm, associated_property, to_string(SerializationMode::Normal));
+}
+
 int StyleValue::to_font_weight() const
 {
     if (is_keyword()) {
diff --git a/Libraries/LibWeb/CSS/StyleValues/StyleValue.h b/Libraries/LibWeb/CSS/StyleValues/StyleValue.h
index 2cfc712bcac..930062d659a 100644
--- a/Libraries/LibWeb/CSS/StyleValues/StyleValue.h
+++ b/Libraries/LibWeb/CSS/StyleValues/StyleValue.h
@@ -207,6 +207,7 @@ public:
 
     virtual String to_string(SerializationMode) const = 0;
     virtual Vector<Parser::ComponentValue> tokenize() const;
+    virtual GC::Ref<CSSStyleValue> reify(JS::Realm&, String const& associated_property) const;
 
     [[nodiscard]] int to_font_weight() const;
     [[nodiscard]] int to_font_slope() const;