diff --git a/lib/puppet/module_tool/applications/builder.rb b/lib/puppet/module_tool/applications/builder.rb
index 25ee6f34b..6ca9cab65 100644
--- a/lib/puppet/module_tool/applications/builder.rb
+++ b/lib/puppet/module_tool/applications/builder.rb
@@ -1,89 +1,93 @@
 require 'fileutils'
 require 'json'
 
 module Puppet::ModuleTool
   module Applications
     class Builder < Application
 
       def initialize(path, options = {})
         @path = File.expand_path(path)
         @pkg_path = File.join(@path, 'pkg')
         super(options)
       end
 
       def run
         load_metadata!
         create_directory
         copy_contents
         write_json
         Puppet.notice "Building #{@path} for release"
         pack
         relative = Pathname.new(archive_file).relative_path_from(Pathname.new(File.expand_path(Dir.pwd)))
 
         # Return the Pathname object representing the path to the release
         # archive just created. This return value is used by the module_tool
         # face build action, and displayed to on the console using the to_s
         # method.
         #
         # Example return value:
         #
         #   <Pathname:puppetlabs-apache/pkg/puppetlabs-apache-0.0.1.tar.gz>
         #
         relative
       end
 
       private
 
       def archive_file
         File.join(@pkg_path, "#{metadata.release_name}.tar.gz")
       end
 
       def pack
         FileUtils.rm archive_file rescue nil
 
         tar = Puppet::ModuleTool::Tar.instance
         Dir.chdir(@pkg_path) do
           tar.pack(metadata.release_name, archive_file)
         end
       end
 
       def create_directory
         FileUtils.mkdir(@pkg_path) rescue nil
         if File.directory?(build_path)
           FileUtils.rm_rf(build_path, :secure => true)
         end
         FileUtils.mkdir(build_path)
       end
 
       def copy_contents
         Dir[File.join(@path, '*')].each do |path|
           case File.basename(path)
           when *Puppet::ModuleTool::ARTIFACTS
             next
           else
             FileUtils.cp_r path, build_path, :preserve => true
           end
         end
       end
 
       def write_json
         metadata_path = File.join(build_path, 'metadata.json')
 
+        if metadata.to_hash.include? 'checksums'
+          Puppet.warning "A 'checksums' field was found in metadata.json. This field will be ignored and can safely be removed."
+        end
+
         # TODO: This may necessarily change the order in which the metadata.json
         # file is packaged from what was written by the user.  This is a
         # regretable, but required for now.
         File.open(metadata_path, 'w') do |f|
           f.write(metadata.to_json)
         end
 
         File.open(File.join(build_path, 'checksums.json'), 'w') do |f|
           f.write(PSON.pretty_generate(Checksums.new(build_path)))
         end
       end
 
       def build_path
         @build_path ||= File.join(@pkg_path, metadata.release_name)
       end
     end
   end
 end