What settings to change in uglify?

Question

gulp.js

There is a task:

gulp.task('scripts', function() {
  return gulp.src([
    dir.assets + '/library/jquery/dist/jquery.js',
    dir.assets + '/library/fotorama/fotorama.js',
    dir.assets + '/js/main.js'
    ])
  .pipe(sourcemaps.init())
  .pipe(concat('scripts.min.js'))
  .pipe(uglify())
  .pipe(gulp.dest(''))
  .pipe(sourcemaps.write('souremaps/'))
  .pipe(browserSync.reload({stream: true}));
});

fotorama stops working, error:
Uncaught TypeError: Cannot read property 'createElement' of undefined
If you disable .pipe(uglify()), then everything works. What option to enable in uglify? Compression options?

Answer 1

Also faced this problem. the solution from here helped me: https://github.com/artpolikarpov/fotorama/issues/528
I took the photo frame script from the comment, and with it everything was compressed and assembled.