diff --git a/README.md b/README.md
index 593379c..2c5ca82 100644
--- a/README.md
+++ b/README.md
@@ -72,13 +72,18 @@ can use the [same Vagrant VirtualBox machine I use for development](#using-virtu
 *Please note that I'm currently using only the quantal x86_64 on a daily basis,
 and I've only done some basic testing with the others*
 
-You can also build a clean box by providing `CHEF=0` and `PUPPET=0` to the available
-[rake tasks](tasks/boxes.rake). For example:
+There is a set of [rake tasks](tasks/boxes.rake) that you can use to build base
+boxes as needed. By default it won't include any provisioning tool and you can
+pick the one you want by providing some environment variables.
+
+For example:
 
 ```
-CHEF=0 PUPPET=0 rake boxes:ubuntu:build:precise64
+CHEF=1 rake boxes:ubuntu:build:precise64
 ```
 
+Will build a Ubuntu Precise x86_64 box with chef pre-installed.
+
 ### Storing container's rootfs on a separate partition
 
 Before the 0.3.0 version of this plugin, there used to be a support for specifying
diff --git a/tasks/boxes.rake b/tasks/boxes.rake
index c9fc162..bdb0242 100644
--- a/tasks/boxes.rake
+++ b/tasks/boxes.rake
@@ -89,9 +89,9 @@ class BuildUbuntuBoxTask < BuildGenericBoxTask
   end
 end
 
-chef     = ENV['CHEF']    != '0'
-puppet   = ENV['PUPPET']  != '0'
-babushka = ENV['BABUSKA'] != '0'
+chef     = ENV['CHEF']     == '1'
+puppet   = ENV['PUPPET']   == '1'
+babushka = ENV['BABUSHKA'] == '1'
 
 namespace :boxes do
   namespace :ubuntu do