diff --git a/examples/rtt_timing.rs b/examples/rtt_timing.rs
index dd647ff19aad8cb3a7c049c6126cd5058b21ceb8..b2642b22a66abb7b89da7f9ad4f4f3e51d172fb4 100644
--- a/examples/rtt_timing.rs
+++ b/examples/rtt_timing.rs
@@ -1,6 +1,6 @@
 //! examples/rtt_timing.rs
 
-// #![deny(unsafe_code)]
+#![deny(unsafe_code)]
 #![deny(warnings)]
 #![no_main]
 #![no_std]