2 files changed, 2 insertions, 1 deletions
diff --git a/src/liballoc/lib.rs b/src/liballoc/lib.rs
index 0493f92bc52..881607f65ba 100644
--- a/src/liballoc/lib.rs
+++ b/src/liballoc/lib.rs
@@ -96,7 +96,7 @@
 #![feature(dropck_eyepatch)]
 #![feature(exact_size_is_empty)]
 #![feature(fmt_internals)]
-#![feature(fn_must_use)]
+#![cfg_attr(stage0, feature(fn_must_use))]
 #![feature(from_ref)]
 #![feature(fundamental)]
 #![feature(lang_items)]
diff --git a/src/liballoc/tests/slice.rs b/src/liballoc/tests/slice.rs
index 99d9c51efc7..6fd0b33f02a 100644
--- a/src/liballoc/tests/slice.rs
+++ b/src/liballoc/tests/slice.rs
@@ -1282,6 +1282,7 @@ fn test_box_slice_clone() {
 }
 
 #[test]
+#[allow(unused_must_use)] // here, we care about the side effects of `.clone()`
 #[cfg_attr(target_os = "emscripten", ignore)]
 fn test_box_slice_clone_panics() {
     use std::sync::Arc;