diff --git a/src/libstd/deque.rs b/src/libstd/deque.rs
index 86304f48e79..18cf64b299f 100644
--- a/src/libstd/deque.rs
+++ b/src/libstd/deque.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+//! A double-ended queue implemented as a circular buffer
+
 use core::container::{Container, Mutable};
 use core::prelude::*;
 use core::vec;