diff --git a/components/style/gecko/selector_parser.rs b/components/style/gecko/selector_parser.rs
index 9be8bf6623d..52549f9ecbe 100644
--- a/components/style/gecko/selector_parser.rs
+++ b/components/style/gecko/selector_parser.rs
@@ -327,7 +327,7 @@ impl<'a, 'i> ::selectors::Parser<'i> for SelectorParser<'a> {
 
     #[inline]
     fn parse_nth_child_of(&self) -> bool {
-        static_prefs::pref!("layout.css.nth-child-of.enabled")
+        true
     }
 
     #[inline]