diff --git a/servo/components/script/dom/bindings/codegen/CodegenRust.py b/servo/components/script/dom/bindings/codegen/CodegenRust.py
index fecc98e8a9a1..5ea35a14541a 100644
--- a/servo/components/script/dom/bindings/codegen/CodegenRust.py
+++ b/servo/components/script/dom/bindings/codegen/CodegenRust.py
@@ -3445,7 +3445,6 @@ class CGUnionStruct(CGThing):
         # XXXManishearth The following should be #[must_root],
         # however we currently allow it till #2661 is fixed
         return ("""\
-#[allow(unrooted_must_root)]
 pub enum %s {
 %s
 }