```ruby
require 'oj' unless defined?(::Oj)

module MultiJson
  module Adapters
    # Use the Oj library to dump/load.
    class Oj
      ParseError = SyntaxError

      ::Oj.default_options = {:mode => :compat}

      def self.load(string, options={}) #:nodoc:
        options.merge!(:symbol_keys => options[:symbolize_keys])
        ::Oj.load(string, options)
      end

      def self.dump(object, options={}) #:nodoc:
        options.merge!(:indent => 2) if options[:pretty]
        ::Oj.dump(object, options)
      end
    end
  end
end
```

Fix Oj ParseError mapping for Oj 1.4.0
user
```ruby
require 'oj' unless defined?(::Oj)

module MultiJson
  module Adapters
    # Use the Oj library to dump/load.
    class Oj
      ParseError = if defined?(::Oj::ParseError)
        ::Oj::ParseError
      else
        SyntaxError
      end

      ::Oj.default_options = {:mode => :compat}

      def self.load(string, options={}) #:nodoc:
        options.merge!(:symbol_keys => options[:symbolize_keys])
        ::Oj.load(string, options)
      end

      def self.dump(object, options={}) #:nodoc:
        options.merge!(:indent => 2) if options[:pretty]
        ::Oj.dump(object, options)
      end
    end
  end
end
```
assistant