diff --git a/src/bin/rustfmt-format-diff.rs b/src/bin/rustfmt-format-diff.rs
index f7f3c1d8f7c..5bd0e5d18cc 100644
--- a/src/bin/rustfmt-format-diff.rs
+++ b/src/bin/rustfmt-format-diff.rs
@@ -19,7 +19,6 @@ extern crate getopts;
 #[macro_use]
 extern crate log;
 extern crate regex;
-extern crate serde;
 #[macro_use]
 extern crate serde_derive;
 extern crate serde_json as json;
diff --git a/src/bin/rustfmt.rs b/src/bin/rustfmt.rs
index 88bd3222fcb..5bb5190e810 100644
--- a/src/bin/rustfmt.rs
+++ b/src/bin/rustfmt.rs
@@ -13,9 +13,7 @@
 
 extern crate env_logger;
 extern crate getopts;
-extern crate log;
 extern crate rustfmt_nightly as rustfmt;
-extern crate toml;
 
 use std::{env, error};
 use std::fs::File;
diff --git a/tests/system.rs b/tests/system.rs
index 6e148147a48..9559b545cc6 100644
--- a/tests/system.rs
+++ b/tests/system.rs
@@ -8,7 +8,6 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
-extern crate diff;
 extern crate regex;
 extern crate rustfmt_nightly as rustfmt;
 extern crate term;