--- /dev/null
+// Copyright 2018 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+#![deny(unknown_features)]
+
+#![feature(unknown_rust_feature)] //~ ERROR unknown feature
+
+fn main() {}
--- /dev/null
+error: unknown feature `unknown_rust_feature`
+ --> $DIR/unknown-feature.rs:13:12
+ |
+LL | #![feature(unknown_rust_feature)] //~ ERROR unknown feature
+ | ^^^^^^^^^^^^^^^^^^^^
+ |
+note: lint level defined here
+ --> $DIR/unknown-feature.rs:11:9
+ |
+LL | #![deny(unknown_features)]
+ | ^^^^^^^^^^^^^^^^
+
+error: aborting due to previous error
+