diff --git a/libcortex_a9/src/lib.rs b/libcortex_a9/src/lib.rs
index 2f341d3..7c9acd3 100644
--- a/libcortex_a9/src/lib.rs
+++ b/libcortex_a9/src/lib.rs
@@ -1,7 +1,7 @@
 #![no_std]
 #![feature(llvm_asm, global_asm)]
 #![feature(never_type)]
-#![feature(const_fn)]
+#![cfg_attr(not(feature = "const_fn"), const_fn)]
 
 extern crate alloc;