README.md in trackler-2.2.1.21 vs README.md in trackler-2.2.1.22

@@ -71,10 +71,10 @@
 ## Adding a new language track
 
 Language tracks are included as submodules. To add a new one, run the following command, defining the track id as an environment variable. Shown here with `prolog` as an example.
 
 ```
-$ TRACK_ID=prolog; git submodule add https://github.com/exercism/x$TRACK_ID tracks/$TRACK_ID
+$ TRACK_ID=prolog; git submodule add https://github.com/exercism/$TRACK_ID tracks/$TRACK_ID
 ```
 
 ## Contributing
 
 Bug reports and pull requests are welcome on GitHub at https://github.com/exercism/trackler. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the [Contributor Covenant](http://contributor-covenant.org) code of conduct.