@@ -187,9 +187,13 @@ you'd like to update.

 > Take note of the container ID that has been created, `0b2616b0e5a8`, as you'll

 > need it in a moment.

-Inside our running container let's add the `json` gem.

+Inside our running container first let's update Ruby:

-    root@0b2616b0e5a8:/# gem install json

+    root@0b2616b0e5a8:/# apt-get install -y ruby2.0-dev

+

+Now let's add the `json` gem.

+

+    root@0b2616b0e5a8:/# gem2.0 install json

 Once this has completed let's exit our container using the `exit`

 command.