Where to put libraryDependencies += javaEbean ?

Quote from the documentation at this page http://www.playframework.com/documentation/2.2.x/JavaEbean :

To enable it, add javaEbean to your dependencies :

libraryDependencies += javaEbean


I don't know in which file to add this line. This is frustrating since there my application is not compiling anymore.
Thanks to precise where to add it.