[Haskell-cafe] Problem with haddock importing definition

Hi, I have a situation like this: module A imports R (a newtype declaration) from module B, and lists it in its (module A) export list. Documentation for R is included by haddock in documentation for module A, as I want. However, if my package exposes only module A, documentation for R desapears. So: if my .cabal file lists A and B in 'exposed-modules', documentation for R is included in A documentation. If I remove B from 'exposed-modules', R documentation in A desapears. Do you know what should I do? Thanks, Maurício