README.md in nugem-0.8.0 vs README.md in nugem-0.8.1

@@ -24,9 +24,15 @@
 
 ```shell
 $ gem install nugem
 ```
 
+If you are using [rbenv](https://github.com/rbenv/rbenv) to manage Ruby instances, type:
+
+```shell
+$ rbenv rehash
+```
+
 To update the program:
 
 ```shell
 $ gem update nugem
 ```