diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index cdfbf4c1..dd3fa01d 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -11,3 +11,10 @@ cargo fmt --all -- --check
 ```
 
 To report a bug, suggest new functionality, or ask a question, go to [Issues](https://github.com/teloxide/teloxide/issues). Try to make MRE (**M**inimal **R**eproducible **E**xample) and specify your teloxide version to let others help you.
+
+
+And don't forget to switch to the nightly channel in order to be able to run `cargo fmt` (because our [rustfmt.toml](https://github.com/teloxide/teloxide/blob/master/rustfmt.toml) requires some nightly-only functionality):
+
+```bash
+$ rustup override set nightly
+```