How to solve this minification error on Gulp? : <p>I'm getting below error running this command</p>

<pre><code>gulp.task('minify', function () {
    return gulp
      .src('public/app/js/myapp.bundle.js')
      .pipe(uglify())
      .pipe(gulp.dest('public/app/js/myapp.bundle.min.js'));
});
</code></pre>

<blockquote>
  <p>GulpUglifyError: unable to minify JavaScript                                                                                      Caused by: SyntaxError: Unexpected token: name (MenuItem) (line: 1628, col: 18, pos: 53569)      </p>
</blockquote>

<p>Code on that location is this</p>

<pre><code> setters: [],
 execute: function () {
     class MenuItem {  // &lt;-- line 1628
</code></pre>

<p>What's wrong?</p>
