Uglifier 4.0+ won't accept 'except' as valid option for mangle

Uglifier.compile(script_content, mangle: { except: ["jQuery"] });

Uglifier::Error -exceptis not a supported option:

Here are the relevant gems:

gem 'rails', '3.2.22.4'
gem 'rake', '~> 12.0'
group :assets do
  gem 'sass-rails',   '~> 3.2.0'
  gem 'coffee-rails', '~> 3.2.0'
  gem 'uglifier', '~> 4'
  gem 'jquery-rails', '~> 3.0'
  gem 'bootstrap-sass', '~> 2.3.2.2'
  gem 'jquery-ui-rails', '~> 6.0'
end

OS is macOS High Sierra, I tried node@6, node@9, node@10, nothing worked until I downgraded to Uglifier 3.

lautis / uglifier

Uglifier 4.0+ won't accept 'except' as valid option for mangle #135