         options.log? "Merge default properties"
         for k, v of options.default
           v = "#{v}" if typeof v is 'number'
-          if typeof v is 'undefined' or v is null
-          then delete fnl_props[k]
-          else fnl_props[k] = v
+          # if typeof v is 'undefined' or v is null
+          # then delete fnl_props[k]
+          # else fnl_props[k] = v
+          fnl_props[k] = v if typeof fnl_props[k] is 'undefined' or fnl_props[k] is null
         do_merge()
       do_merge = () ->
         options.log? "Merge user properties"

        options.source = null
        mecano.write options, (err, written) ->
          next err
      conditions.all options, next, do_read
    .on 'both', (err) ->
      finish err, configured
  result

        return do_merge() unless options.default
        return do_default() unless typeof options.default is 'string'
        options.log? "Read default properties from #{options.default}"
        # Populate options.default
        ssh = if options.local_default then null else options.ssh
        properties.read ssh, options.default, (err, dft) ->
          return next err if err
