diff --git a/tokio-io/tests/length_delimited.rs b/tokio-io/tests/length_delimited.rs
index 985a08361..f3796654a 100644
--- a/tokio-io/tests/length_delimited.rs
+++ b/tokio-io/tests/length_delimited.rs
@@ -1,3 +1,6 @@
+// This file is testing deprecated code.
+#![allow(deprecated)]
+
 extern crate tokio_io;
 extern crate futures;