{} in .cabal for Haddock-documentation in Haskell

If I got the line

> { -# OPTIONS_GHC -fglasgow-exts -XTemplateHaskell #- }

in the documentation-part (description) of the .cabal-file I'll get the error message

haddock: parsing haddock prologue failed

when running

$ cabal haddock

but if I get rid of the { and } everything works fine. Is there some way to escape {} so they can be used in the description?