diff --git a/src/lib.rs b/src/lib.rs
index 94dcac52..0955a475 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,6 @@
 #![doc(html_root_url = "https://docs.rs/hyper/0.11.1")]
 #![deny(missing_docs)]
-//#![deny(warnings)]
+#![deny(warnings)]
 #![deny(missing_debug_implementations)]
 #![cfg_attr(all(test, feature = "nightly"), feature(test))]