diff --git a/components/script/dom/bindings/conversions.rs b/components/script/dom/bindings/conversions.rs
index c84adf64dbb..0b826886a7a 100644
--- a/components/script/dom/bindings/conversions.rs
+++ b/components/script/dom/bindings/conversions.rs
@@ -74,7 +74,6 @@ pub trait IDLInterface {
 }
 
 /// A trait to mark an IDL interface as deriving from another one.
-#[rustc_on_unimplemented(message = "The IDL interface `{Self}` is not derived from `{T}`.")]
 pub trait DerivedFrom<T: Castable>: Castable {}
 
 impl<T: Float + ToJSValConvertible> ToJSValConvertible for Finite<T> {
diff --git a/components/script/lib.rs b/components/script/lib.rs
index 48f42cd7a38..250f860eda2 100644
--- a/components/script/lib.rs
+++ b/components/script/lib.rs
@@ -6,7 +6,6 @@
 #![feature(core_intrinsics)]
 #![feature(drain_filter)]
 #![feature(inner_deref)]
-#![feature(on_unimplemented)]
 #![feature(plugin)]
 #![deny(unsafe_code)]
 #![allow(non_snake_case)]