diff --git a/servo/components/config/opts.rs b/servo/components/config/opts.rs
index 158e2850f587..45663c458274 100644
--- a/servo/components/config/opts.rs
+++ b/servo/components/config/opts.rs
@@ -448,6 +448,7 @@ pub fn multiprocess() -> bool {
 enum UserAgent {
     Desktop,
     Android,
+    #[allow(non_camel_case_types)]
     iOS
 }