How to have duplicate module name in a different folder?

I want to nest my modules like this

payment
   contract
   impl
transaction
   contract
   impl

i.e. payment:contract, payment:impl, transaction:contract, transaction:impl But gradle complains about there being duplicate impl module (and contract)

More than one file was found with OS independent path 'META-INF/impl_debug.kotlin_module'.

how can I do this, without renaming it to transaction:transaction-contract or not nesting?