diff --git a/components/style/counter_style/mod.rs b/components/style/counter_style/mod.rs
index 570ef06ab1b..0d2c4e8e674 100644
--- a/components/style/counter_style/mod.rs
+++ b/components/style/counter_style/mod.rs
@@ -391,7 +391,7 @@ impl ToCss for System {
 
 /// <https://drafts.csswg.org/css-counter-styles/#typedef-symbol>
 #[cfg_attr(feature = "gecko", derive(MallocSizeOf))]
-#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue)]
+#[derive(Clone, Debug, Eq, PartialEq, ToComputedValue, ToCss)]
 pub enum Symbol {
     /// <string>
     String(String),
@@ -417,18 +417,6 @@ impl Parse for Symbol {
     }
 }
 
-impl ToCss for Symbol {
-    fn to_css<W>(&self, dest: &mut CssWriter<W>) -> fmt::Result
-    where
-        W: Write,
-    {
-        match *self {
-            Symbol::String(ref s) => s.to_css(dest),
-            Symbol::Ident(ref s) => s.to_css(dest),
-        }
-    }
-}
-
 impl Symbol {
     /// Returns whether this symbol is allowed in symbols() function.
     pub fn is_allowed_in_symbols(&self) -> bool {