Hi, A recent change in the compiler means that function names are now desugared differently. In particularly: module Foo where bar = .... Used to generate Foo.bar, now it generates Foo;bar. As a result, anyone who was using the Overlay mechanism to match certain names will have to change their overlay file. For example: foreign import primitive global_Prelude'_seq :: a -> b -> b becomes: foreign import primitive global_Prelude''seq :: a -> b -> b I have changed '' to be an alias for ;, and made 'ap be an alias for ' Any questions, feel free to contact me. Thanks Neil