Hello, $ ghc --version The Glorious Glasgow Haskell Compilation System, version 6.7.20070915 When loading the following incorrect program in ghci: foo (x :: a) = x ghci rightly complains: Illegal signature in pattern: a Use -XPatternSigs to permit it OK so I follow the advice and load: {-# OPTIONS_GHC -XPatternSigs #-} foo (x :: a) = x Now ghci complains: unknown flags in {-# OPTIONS #-} pragma: -XPatternSigs ??? The following works though: {-# OPTIONS_GHC -fglasgow-exts #-} foo (x :: a) = x results in: A pattern type signature cannot bind scoped type variables `a' unless the pattern has a rigid type context In the pattern: x :: a In the definition of `foo': foo (x :: a) = x Which I expect. Should I file a bug report, or is there an easy fix? regards, Bas van Dijk