You want to change the default package provider for your systems.
# in your site.pp
Package { provider => "aptrpm" }
Not all package providers are created equal. Some of them, as shown in the table under packages, have additional functionality that you may want. Changing the provider is simple, including a line like the above somewhere high up in your configuration file chain (such as site.pp) will ensure all the declared package types use the newly chosen provider.