diff --git a/README.md b/README.md
index a642afa6..92b63566 100644
--- a/README.md
+++ b/README.md
@@ -6,6 +6,14 @@ ruma-signatures provides functionality for creating digital signatures according
 
 ruma-signatures has [comprehensive documentation](https://docs.rs/ruma-signatures) available on docs.rs.
 
+## Minimum Rust version
+
+ruma-client-api is only guaranteed to work on the latest stable version of Rust.
+
+This support policy is inherited from the dependency on [ring][].
+
+[ring]: https://github.com/briansmith/ring/
+
 ## License
 
 [MIT](http://opensource.org/licenses/MIT)