diff --git a/src/ns.rs b/src/ns.rs
index 7ba4d3e1..d1a3dabb 100644
--- a/src/ns.rs
+++ b/src/ns.rs
@@ -1,3 +1,5 @@
+//! Provides constants for namespaces.
+
 pub const CLIENT: &'static str = "jabber:client";
 pub const STREAM: &'static str = "http://etherx.jabber.org/streams";
 pub const TLS: &'static str = "urn:ietf:params:xml:ns:xmpp-tls";