[Haskell-cafe] build-depends contraints in a .cabal file

Can I specify an equality constraint in the build-depends field of a .cabal file? This would say that I want one specific version (because all the rest of my packages are compiled against that version and I'm getting type-checking errors trying to install the new package). neither

build-depends: foobar = 3.0.1

or

build-depends: foobar-3.0.1

seem to work. Do I have any choices other than re-compiling everything? Thanks, Antoine