1 files changed, 1 insertions, 0 deletions
diff --git a/src/lib.rs b/src/lib.rs
index a1a911ae..ba251ef3 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -30,6 +30,7 @@
 //! [SemVer]: https://semver.org/spec/v2.0.0.html
 
 #![deny(missing_docs)]
+#![deny(rust_2021_compatibility)]
 #![deny(rust_2018_compatibility)]
 #![deny(rust_2018_idioms)]
 #![no_std]