diff --git a/examples/echo-udp.rs b/examples/echo-udp.rs
index f95fbd3e9..0b9004df9 100644
--- a/examples/echo-udp.rs
+++ b/examples/echo-udp.rs
@@ -9,7 +9,7 @@
 //! and in another terminal you can run:
 //!
 //! ```sh
-//! $ nc -u localhost 8080
+//! $ nc -4u localhost 8080
 //! ```
 //!
 //! Each line you type in to the `nc` terminal should be echo'd back to you!