diff --git a/Cargo.lock b/Cargo.lock
index f5f4333..9a113b3 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -1,6 +1,6 @@
 [[package]]
 name = "byteorder"
-version = "1.2.1"
+version = "1.2.6"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
 [[package]]
@@ -26,13 +26,13 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 name = "w5500"
 version = "0.1.5"
 dependencies = [
- "byteorder 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)",
  "embedded-hal 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
  "nb 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
 [metadata]
-"checksum byteorder 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "652805b7e73fada9d85e9a6682a4abd490cb52d96aeecc12e33a0de34dfd0d23"
+"checksum byteorder 1.2.6 (registry+https://github.com/rust-lang/crates.io-index)" = "90492c5858dd7d2e78691cfb89f90d273a2800fc11d98f60786e5d87e2f83781"
 "checksum embedded-hal 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)" = "26944677e4934eb5fb4025501dc0d6cdbcf6bfabd6200fcfee2e7e8eef8c0362"
 "checksum nb 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "69f380b5fe9fab8c0d7a6a99cda23e2cc0463bedb2cbc3aada0813b98496ecdc"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
diff --git a/src/lib.rs b/src/lib.rs
index 8b5083d..c25a088 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,5 @@
 #![no_std]
 #![allow(unused)]
-#![feature(const_fn)]
 
 extern crate byteorder;
 extern crate embedded_hal as hal;