diff --git a/config_defaults.yml b/config_defaults.yml
index 0b1843eb..cd78b3df 100644
--- a/config_defaults.yml
+++ b/config_defaults.yml
@@ -12,3 +12,36 @@
     env: PUPPET_GEM_VERSION="~> 3.0" FUTURE_PARSER="yes"
   - rvm: 2.1.6
     env: PUPPET_GEM_VERSION="~> 4.0" STRICT_VARIABLES="yes"
+Gemfile:
+  required:
+    ':test':
+      - gem: rake
+      - gem: rspec-puppet
+        git: https://github.com/rodjek/rspec-puppet.git
+      - gem: puppetlabs_spec_helper
+      - gem: metadata-json-lint
+      - gem: rspec-puppet-facts
+      - gem: rspec
+      - gem: puppet-blacksmith
+      - gem: rubocop
+      - gem: rspec-puppet-utils
+      - gem: puppet
+        version: ENV['PUPPET_VERSION'] || '~> 3.8.0'
+      - gem: rspec-puppet-augeas
+      - gem: ruby-augeas
+      - gem: puppetlabs_spec_helper
+      - gem: puppet-lint-absolute_classname-check
+      - gem: puppet-lint-leading_zero-check
+      - gem: puppet-lint-trailing_comma-check
+      - gem: puppet-lint-version_comparison-check
+      - gem: puppet-lint-classes_and_types_beginning_with_digits-check
+      - gem: puppet-lint-unquoted_string-check
+      - gem: puppet-lint-variable_contains_upcase
+    ':development':
+      - gem: travis
+      - gem: travis-lint
+      - gem: guard-rake
+    ':system_tests':
+      - gem: beaker
+      - gem: beaker-rspec
+...
diff --git a/moduleroot/Gemfile b/moduleroot/Gemfile
index eb947bf7..21740a74 100644
--- a/moduleroot/Gemfile
+++ b/moduleroot/Gemfile
@@ -1,33 +1,61 @@
-source 'https://rubygems.org'
+source ENV['GEM_SOURCE'] || 'https://rubygems.org'
 
-group :test do
-  gem 'rake'
-  gem 'puppet', ENV['PUPPET_VERSION'] || '~> 3.8.0'
-  gem 'rspec-puppet', git: 'https://github.com/rodjek/rspec-puppet.git'
-  gem 'rspec-puppet-augeas'
-  gem 'ruby-augeas'
-  gem 'puppetlabs_spec_helper'
-  gem 'metadata-json-lint'
-  gem 'rspec-puppet-facts'
-  gem 'rspec'
-  gem 'puppet-blacksmith'
-  gem 'rubocop'
-  gem 'puppet-lint-absolute_classname-check'
-  gem 'puppet-lint-leading_zero-check'
-  gem 'puppet-lint-trailing_comma-check'
-  gem 'puppet-lint-version_comparison-check'
-  gem 'puppet-lint-classes_and_types_beginning_with_digits-check'
-  gem 'puppet-lint-unquoted_string-check'
-  gem 'puppet-lint-variable_contains_upcase'
+def location_for(place, fake_version = nil)
+  if place =~ /^(git[:@][^#]*)#(.*)/
+    [fake_version, { :git => $1, :branch => $2, :require => false }].compact
+  elsif place =~ /^file:\/\/(.*)/
+    ['>= 0', { :path => File.expand_path($1), :require => false }]
+  else
+    [place, { :require => false }]
+  end
 end
 
-group :development do
-  gem 'travis'
-  gem 'travis-lint'
-  gem 'guard-rake'
+<% groups = {} -%>
+<% (@configs['required'].keys + ((@configs['optional'] || {}).keys)).uniq.each do |key| -%>
+<%   groups[key] = (@configs['required'][key] || []) + ((@configs['optional'] || {})[key] || []) -%>
+<% end -%>
+<% -%>
+<% groups.each do |group, gems| -%>
+group <%= group %> do
+<% maxlen = gems.map! do |gem| -%>
+<%            { -%>
+<%              'gem'     => gem['gem'], -%>
+<%              'version' => gem['version'], -%>
+<%              'git'     => gem['git'], -%>
+<%              'branch'  => gem['branch'], -%>
+<%              'length'  => gem['gem'].length + (("', '".length if gem['version']) || 0) + gem['version'].to_s.length -%>
+<%            } -%>
+<%          end.map do |gem| -%>
+<%            gem['length'] -%>
+<%          end.max -%>
+<% gems.each do |gem| -%>
+<% if gem['gem'] == 'beaker-rspec' -%>
+  if beaker_version = ENV['BEAKER_VERSION']
+    gem 'beaker', *location_for(beaker_version)
+  end
+  if beaker_rspec_version = ENV['BEAKER_RSPEC_VERSION']
+    gem 'beaker-rspec', *location_for(beaker_rspec_version)
+  else
+    gem 'beaker-rspec',  :require => false
+  end
+<% else -%>
+  gem '<%= gem['gem'] %>'<%= ", '#{gem['version']}'" if gem['version'] %>, <%= ' ' * (maxlen - gem['length']) %> :require => false<%= ", :git => '#{gem['git']}'" if gem['git'] %><%= ", :branch => '#{gem['branch']}'" if gem['branch'] %>
+<% end -%>
+<% end -%>
 end
 
-group :system_tests do
-  gem 'beaker'
-  gem 'beaker-rspec'
+<% end -%>
+
+if facterversion = ENV['FACTER_GEM_VERSION']
+  gem 'facter', facterversion, :require => false
+else
+  gem 'facter', :require => false
+end
+
+if puppetversion = ENV['PUPPET_GEM_VERSION']
+  gem 'puppet', puppetversion, :require => false
+else
+  gem 'puppet', 3.8.0, :require => false
 end
+
+# vim:ft=ruby