diff --git a/README.md b/README.md
index 10b01e4..7b52a3e 100644
--- a/README.md
+++ b/README.md
@@ -92,7 +92,9 @@ A more complete reference can be found on [the website](https://kalker.xyz)
 
 ## kalk and cli (Rust)
 
-After making changes to the kalk library (in `kalk/`), you can easily try them out by going to the root of the project directory, and doing `cargo run`. This will start kalker (cli), with the new changes. If you're using Windows, you will need to [follow the instructions here](https://docs.rs/gmp-mpfr-sys/1.2.3/gmp_mpfr_sys/index.html#building-on-windows), but also make sure to install `mingw-w64-x86_64-rust` in MSYS2. 
+After making changes to the kalk library (in `kalk/`), you can easily try them out by going to the root of the project directory, and doing `cargo run`. This will start kalker (cli), with the new changes. If you're using Windows, you will need to [follow the instructions here](https://docs.rs/gmp-mpfr-sys/1.2.3/gmp_mpfr_sys/index.html#building-on-windows), but also make sure to install `mingw-w64-x86_64-rust` in MSYS2.
+
+All Rust code is expected to be formatted with `rustfmt
 
 ## web (Svelte, TypeScript, Sass)