diff --git a/src/lib.rs b/src/lib.rs
index 5015fe9..73e1bda 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,10 +1,8 @@
 //! Definitions of register addresses and bits within those registers
 
 #![feature(llvm_asm)]
-#![feature(const_fn)]
 #![feature(associated_type_defaults)]
 #![feature(lang_items)]
-#![feature(unwind_attributes)]
 #![feature(proc_macro_hygiene)]
 
 #![no_std]