TypeError: Object.values is not a function

[olivermanumbas]

\node_modules\node-rake\index.js:63 Object.values(wordFreq).forEach((freq) => { wordDegree[freq] += wordFreq[freq]; }); ^

TypeError: Object.values is not a function at Rake.calculateKeywordScores (C:\Users\john.manumbas\Desktop\bots\Sample Node\node_modules\node-rake\index.js:63:12) at Rake.generate (C:\Users\john.manumbas\Desktop\bots\Sample Node\node_modules\node-rake\index.js:88:29) at Object.generate (C:\Users\john.manumbas\Desktop\bots\Sample Node\node_modules\node-rake\app.js:13:21) at Object. (C:\Users\john.manumbas\Desktop\bots\Sample Node\SpeechAPI\node_rake_sample.js:4:23) at Module._compile (module.js:570:32) at Object.Module._extensions..js (module.js:579:10) at Module.load (module.js:487:32) at tryModuleLoad (module.js:446:12) at Function.Module._load (module.js:438:3) at Module.runMain (module.js:604:10)

Node Version: v6.10.3