Distance Matrix URL returns ?origin=*&destination=*key=* instead of ?origins=*&destinations=*key=*

When making a distancematrix() request the URL that is returned is incorrect as it has "origin" and "destination" instead of "origins" and "destinations".

This returns status 'INVALID_REQUEST'. If I copy the URL in to a browser and change origin to origins and destination to destinations in the url data is pulled correctly.