How to work with a boss that evaluates productivity by Lines of Code(LOC)?

The new boss at my team majorly evaluates the productivity by counting lines of code. So if I am doing mantainance or bugfix, the code change is small and my rate is low. However, if I do adding new code or new feature, that code change shall be big and get performance improved.

The question is how to work better with boss that always compliane your LOC does not meet the productivity standard?