diff --git a/src/libcore/tests/lib.rs b/src/libcore/tests/lib.rs
index e034ff805934..ada61d8dfd87 100644
--- a/src/libcore/tests/lib.rs
+++ b/src/libcore/tests/lib.rs
@@ -19,6 +19,7 @@
 #![feature(flt2dec)]
 #![feature(fmt_internals)]
 #![feature(hashmap_internals)]
+#![feature(impl_header_lifetime_elision)]
 #![feature(pattern)]
 #![feature(range_is_empty)]
 #![feature(raw)]