diff --git a/docs/CONTRIBUTING.md b/docs/CONTRIBUTING.md
index a46cfcd66..f3cf351dc 100644
--- a/docs/CONTRIBUTING.md
+++ b/docs/CONTRIBUTING.md
@@ -128,8 +128,12 @@ run(
     ),
     RunOpts(log=Log.BOTH, prefix=machine.name, needs_user_terminal=True),
 )
+
 ```
 
+The <path_to_local_src> doesn't need to be a local path, it can be any valid [flakeref](https://nix.dev/manual/nix/2.26/command-ref/new-cli/nix3-flake.html#flake-references).
+And thus can point test already opened PRs for example.
+
 # Standards
 
 - Every new module name should be in kebab-case.