winston.js info method not passing metadata

When I'm passing metadata through winston the shortcut winston.info method isn't passing along the metadata.

var winston = require('winston');

winston.info("winston with metadata", {cluster: "bar"});
winston.log("info", "winston with metadata", {cluster: "baz"});

OUTPUT:

info: winston with metadata
info: winston with metadata cluster=baz

I'd expect both calls to print out the metadata?

Digging through winston code it looks like it dynamically generates the shortcut functions for each level ('info', 'debug', 'error'), and tries to handle additional metadata arguments:

//
// ### function setLevels (target, past, current)
// #### @target {Object} Object on which to set levels.
// #### @past {Object} Previous levels set on target.
// #### @current {Object} Current levels to set on target.
// Create functions on the target objects for each level
// in current.levels. If past is defined, remove functions
// for each of those levels.
//
exports.setLevels = function (target, past, current, isDefault) {
  if (past) {
    Object.keys(past).forEach(function (level) {
      delete target[level];
    });
  }

  target.levels = current || config.npm.levels;
  if (target.padLevels) {
    target.levelLength = exports.longestElement(Object.keys(target.levels));
  }

  //
  //  Define prototype methods for each log level
  //  e.g. target.log('info', msg) <=> target.info(msg)
  //
  Object.keys(target.levels).forEach(function (level) {
    target[level] = function (msg) {
      var args = Array.prototype.slice.call(arguments, 1),
          callback = args.pop(),
          ltype = typeof callback,
          meta = args.length ? args : null;

      if (ltype !== 'function') {
        if (meta && ltype !== 'undefined') {
          meta.push(callback);
        }

        callback = null;
      }

      if (meta) {
        meta = (meta.length <= 1 && meta.shift()) || meta;
        return callback
          ? target.log(level, msg, meta, callback)
          : target.log(level, msg, meta)
      }

      return callback
        ? target.log(level, msg, callback)
        : target.log(level, msg)
    };
  });

  return target;
};