diff --git a/Cargo.toml b/Cargo.toml
index 3a931f218..f2e1bb7ba 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -1,6 +1,7 @@
 [package]
 name = "actix-protobuf"
 version = "0.4.1"
+edition = "2018"
 authors = ["kingxsp <jin.hb.zh@outlook.com>"]
 description = "Protobuf support for actix-web framework."
 readme = "README.md"
diff --git a/src/lib.rs b/src/lib.rs
index f8bb3317a..ee6648242 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,17 +1,3 @@
-extern crate actix;
-extern crate actix_web;
-extern crate bytes;
-extern crate derive_more;
-extern crate futures;
-
-#[cfg(test)]
-extern crate http;
-
-extern crate prost;
-#[cfg(test)]
-#[macro_use]
-extern crate prost_derive;
-
 use derive_more::Display;
 use std::fmt;
 use std::ops::{Deref, DerefMut};