diff --git a/Userland/Libraries/LibWeb/CMakeLists.txt b/Userland/Libraries/LibWeb/CMakeLists.txt
index 8bd8b2bd67..983a307414 100644
--- a/Userland/Libraries/LibWeb/CMakeLists.txt
+++ b/Userland/Libraries/LibWeb/CMakeLists.txt
@@ -93,6 +93,7 @@ set(SOURCES
     CSS/StyleValues/PositionStyleValue.cpp
     CSS/StyleValues/RadialGradientStyleValue.cpp
     CSS/StyleValues/ShadowStyleValue.cpp
+    CSS/StyleValues/TextDecorationStyleValue.cpp
     CSS/Supports.cpp
     CSS/SyntaxHighlighter/SyntaxHighlighter.cpp
     CSS/Time.cpp
diff --git a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
index 557dfdf69a..466178e169 100644
--- a/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
+++ b/Userland/Libraries/LibWeb/CSS/Parser/Parser.cpp
@@ -64,6 +64,7 @@
 #include <LibWeb/CSS/StyleValues/ResolutionStyleValue.h>
 #include <LibWeb/CSS/StyleValues/ShadowStyleValue.h>
 #include <LibWeb/CSS/StyleValues/StringStyleValue.h>
+#include <LibWeb/CSS/StyleValues/TextDecorationStyleValue.h>
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/Dump.h>
 #include <LibWeb/Infra/Strings.h>
diff --git a/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp b/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
index 906320f753..24afe8e3fa 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
+++ b/Userland/Libraries/LibWeb/CSS/StyleComputer.cpp
@@ -43,6 +43,7 @@
 #include <LibWeb/CSS/StyleValues/NumericStyleValue.h>
 #include <LibWeb/CSS/StyleValues/OverflowStyleValue.h>
 #include <LibWeb/CSS/StyleValues/PercentageStyleValue.h>
+#include <LibWeb/CSS/StyleValues/TextDecorationStyleValue.h>
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/DOM/Element.h>
 #include <LibWeb/FontCache.h>
diff --git a/Userland/Libraries/LibWeb/CSS/StyleValue.cpp b/Userland/Libraries/LibWeb/CSS/StyleValue.cpp
index 9354b1ba17..82017b1ce4 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleValue.cpp
+++ b/Userland/Libraries/LibWeb/CSS/StyleValue.cpp
@@ -47,6 +47,7 @@
 #include <LibWeb/CSS/StyleValues/ResolutionStyleValue.h>
 #include <LibWeb/CSS/StyleValues/ShadowStyleValue.h>
 #include <LibWeb/CSS/StyleValues/StringStyleValue.h>
+#include <LibWeb/CSS/StyleValues/TextDecorationStyleValue.h>
 #include <LibWeb/DOM/Document.h>
 #include <LibWeb/HTML/BrowsingContext.h>
 #include <LibWeb/Loader/LoadRequest.h>
@@ -1148,11 +1149,6 @@ ErrorOr<String> RectStyleValue::to_string() const
     return String::formatted("rect({} {} {} {})", m_rect.top_edge, m_rect.right_edge, m_rect.bottom_edge, m_rect.left_edge);
 }
 
-ErrorOr<String> TextDecorationStyleValue::to_string() const
-{
-    return String::formatted("{} {} {} {}", TRY(m_properties.line->to_string()), TRY(m_properties.thickness->to_string()), TRY(m_properties.style->to_string()), TRY(m_properties.color->to_string()));
-}
-
 ErrorOr<String> TransformationStyleValue::to_string() const
 {
     StringBuilder builder;
diff --git a/Userland/Libraries/LibWeb/CSS/StyleValue.h b/Userland/Libraries/LibWeb/CSS/StyleValue.h
index 11eab4ea40..eab2ce6fe0 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleValue.h
+++ b/Userland/Libraries/LibWeb/CSS/StyleValue.h
@@ -622,47 +622,6 @@ private:
     NonnullOwnPtr<CalcSum> m_expression;
 };
 
-class TextDecorationStyleValue final : public StyleValueWithDefaultOperators<TextDecorationStyleValue> {
-public:
-    static ValueComparingNonnullRefPtr<TextDecorationStyleValue> create(
-        ValueComparingNonnullRefPtr<StyleValue> line,
-        ValueComparingNonnullRefPtr<StyleValue> thickness,
-        ValueComparingNonnullRefPtr<StyleValue> style,
-        ValueComparingNonnullRefPtr<StyleValue> color)
-    {
-        return adopt_ref(*new TextDecorationStyleValue(move(line), move(thickness), move(style), move(color)));
-    }
-    virtual ~TextDecorationStyleValue() override = default;
-
-    ValueComparingNonnullRefPtr<StyleValue> line() const { return m_properties.line; }
-    ValueComparingNonnullRefPtr<StyleValue> thickness() const { return m_properties.thickness; }
-    ValueComparingNonnullRefPtr<StyleValue> style() const { return m_properties.style; }
-    ValueComparingNonnullRefPtr<StyleValue> color() const { return m_properties.color; }
-
-    virtual ErrorOr<String> to_string() const override;
-
-    bool properties_equal(TextDecorationStyleValue const& other) const { return m_properties == other.m_properties; }
-
-private:
-    TextDecorationStyleValue(
-        ValueComparingNonnullRefPtr<StyleValue> line,
-        ValueComparingNonnullRefPtr<StyleValue> thickness,
-        ValueComparingNonnullRefPtr<StyleValue> style,
-        ValueComparingNonnullRefPtr<StyleValue> color)
-        : StyleValueWithDefaultOperators(Type::TextDecoration)
-        , m_properties { .line = move(line), .thickness = move(thickness), .style = move(style), .color = move(color) }
-    {
-    }
-
-    struct Properties {
-        ValueComparingNonnullRefPtr<StyleValue> line;
-        ValueComparingNonnullRefPtr<StyleValue> thickness;
-        ValueComparingNonnullRefPtr<StyleValue> style;
-        ValueComparingNonnullRefPtr<StyleValue> color;
-        bool operator==(Properties const&) const = default;
-    } m_properties;
-};
-
 class TimeStyleValue : public StyleValueWithDefaultOperators<TimeStyleValue> {
 public:
     static ValueComparingNonnullRefPtr<TimeStyleValue> create(Time time)
diff --git a/Userland/Libraries/LibWeb/CSS/StyleValues/TextDecorationStyleValue.cpp b/Userland/Libraries/LibWeb/CSS/StyleValues/TextDecorationStyleValue.cpp
new file mode 100644
index 0000000000..722ab84629
--- /dev/null
+++ b/Userland/Libraries/LibWeb/CSS/StyleValues/TextDecorationStyleValue.cpp
@@ -0,0 +1,19 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2021, Tobias Christiansen <tobyase@serenityos.org>
+ * Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>
+ * Copyright (c) 2022-2023, MacDue <macdue@dueutil.tech>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include "TextDecorationStyleValue.h"
+
+namespace Web::CSS {
+
+ErrorOr<String> TextDecorationStyleValue::to_string() const
+{
+    return String::formatted("{} {} {} {}", TRY(m_properties.line->to_string()), TRY(m_properties.thickness->to_string()), TRY(m_properties.style->to_string()), TRY(m_properties.color->to_string()));
+}
+
+}
diff --git a/Userland/Libraries/LibWeb/CSS/StyleValues/TextDecorationStyleValue.h b/Userland/Libraries/LibWeb/CSS/StyleValues/TextDecorationStyleValue.h
new file mode 100644
index 0000000000..b3a6ace4bc
--- /dev/null
+++ b/Userland/Libraries/LibWeb/CSS/StyleValues/TextDecorationStyleValue.h
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2018-2020, Andreas Kling <kling@serenityos.org>
+ * Copyright (c) 2021, Tobias Christiansen <tobyase@serenityos.org>
+ * Copyright (c) 2021-2023, Sam Atkins <atkinssj@serenityos.org>
+ * Copyright (c) 2022-2023, MacDue <macdue@dueutil.tech>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <LibWeb/CSS/StyleValue.h>
+
+namespace Web::CSS {
+
+class TextDecorationStyleValue final : public StyleValueWithDefaultOperators<TextDecorationStyleValue> {
+public:
+    static ValueComparingNonnullRefPtr<TextDecorationStyleValue> create(
+        ValueComparingNonnullRefPtr<StyleValue> line,
+        ValueComparingNonnullRefPtr<StyleValue> thickness,
+        ValueComparingNonnullRefPtr<StyleValue> style,
+        ValueComparingNonnullRefPtr<StyleValue> color)
+    {
+        return adopt_ref(*new TextDecorationStyleValue(move(line), move(thickness), move(style), move(color)));
+    }
+    virtual ~TextDecorationStyleValue() override = default;
+
+    ValueComparingNonnullRefPtr<StyleValue> line() const { return m_properties.line; }
+    ValueComparingNonnullRefPtr<StyleValue> thickness() const { return m_properties.thickness; }
+    ValueComparingNonnullRefPtr<StyleValue> style() const { return m_properties.style; }
+    ValueComparingNonnullRefPtr<StyleValue> color() const { return m_properties.color; }
+
+    virtual ErrorOr<String> to_string() const override;
+
+    bool properties_equal(TextDecorationStyleValue const& other) const { return m_properties == other.m_properties; }
+
+private:
+    TextDecorationStyleValue(
+        ValueComparingNonnullRefPtr<StyleValue> line,
+        ValueComparingNonnullRefPtr<StyleValue> thickness,
+        ValueComparingNonnullRefPtr<StyleValue> style,
+        ValueComparingNonnullRefPtr<StyleValue> color)
+        : StyleValueWithDefaultOperators(Type::TextDecoration)
+        , m_properties { .line = move(line), .thickness = move(thickness), .style = move(style), .color = move(color) }
+    {
+    }
+
+    struct Properties {
+        ValueComparingNonnullRefPtr<StyleValue> line;
+        ValueComparingNonnullRefPtr<StyleValue> thickness;
+        ValueComparingNonnullRefPtr<StyleValue> style;
+        ValueComparingNonnullRefPtr<StyleValue> color;
+        bool operator==(Properties const&) const = default;
+    } m_properties;
+};
+
+}