diff --git a/src/lib.rs b/src/lib.rs
index 53824ae5..45320370 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1,6 +1,7 @@
 //! Crate **ruma_identifiers** contains types for [Matrix](https://matrix.org/) identifiers
 //! for events, rooms, room aliases, room versions, and users.
 
+#![warn(rust_2018_idioms)]
 #![deny(
     missing_copy_implementations,
     missing_debug_implementations,