diff --git a/Userland/Libraries/LibWeb/CSS/StyleValue.h b/Userland/Libraries/LibWeb/CSS/StyleValue.h
index 180c5a4e2c..24d48ea986 100644
--- a/Userland/Libraries/LibWeb/CSS/StyleValue.h
+++ b/Userland/Libraries/LibWeb/CSS/StyleValue.h
@@ -1401,6 +1401,17 @@ public:
 
     virtual String to_string() const override;
 
+    virtual bool equals(StyleValue const& other) const override
+    {
+        if (type() != other.type())
+            return false;
+        auto const& typed_other = static_cast<PositionStyleValue const&>(other);
+        return m_edge_x == typed_other.m_edge_x
+            && m_offset_x == typed_other.m_offset_x
+            && m_edge_y == typed_other.m_edge_y
+            && m_offset_y == typed_other.m_offset_y;
+    }
+
 private:
     PositionStyleValue(PositionEdge edge_x, LengthPercentage const& offset_x, PositionEdge edge_y, LengthPercentage const& offset_y)
         : StyleValue(Type::Position)