diff --git a/src/lib.rs b/src/lib.rs
index 0554a746..a35a4ffc 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -45,13 +45,7 @@
 //! This crate has one optional feature: `test`. The `test` feature will enable
 //! the `test` module which contains testing facilities.
 
-#![feature(
-    const_option,
-    doc_auto_cfg,
-    doc_cfg_hide,
-    impl_trait_in_assoc_type,
-    never_type
-)]
+#![feature(const_option, doc_auto_cfg, doc_cfg_hide, never_type)]
 #![warn(
     anonymous_parameters,
     bare_trait_objects,