diff --git a/values.rs b/values.rs
index 50e3e15..77bd0c6 100644
--- a/values.rs
+++ b/values.rs
@@ -58,7 +58,7 @@ pub enum CSSBorderColor {
     CSSBorderColorTransparent
 }
 
-#[deriving(Eq)]
+#[deriving(Eq, Clone)]
 pub enum CSSBorderStyle {
     CSSBorderStyleNone,
     CSSBorderStyleHidden,