diff --git a/lib/fpm/cookery/utils.rb b/lib/fpm/cookery/utils.rb
index a0aa326d..93296cc6 100644
--- a/lib/fpm/cookery/utils.rb
+++ b/lib/fpm/cookery/utils.rb
@@ -24,11 +24,10 @@ def argument_build(*args)
         if args.last.is_a?(Hash)
           opts = args.pop
           args += opts.map{ |k,v|
-            option = k.to_s.gsub('_','-')
             if v == true
-              "--#{option}"
+              "--#{k}"
             else
-              "--#{option}=#{v}"
+              "--#{k}=#{v}"
             end
           }
         end