[Haskell-cafe] -Werror -Woverlapping-patterns -fglasgow-exts ?

Dear Cafe, I want to chase overlapping patterns in a larger code base. So I use -Werror -Woverlapping-patterns . But the code also needs -fglasgow-exts and this makes compilation stop right at the beginning, with "warning: -fglasgow-exts is deprecated: ..." which will be turned into an error because of -Werror -Wno-warnings-deprecations does not help, apparently that warning is not a deprecation. Is there a way to get -Werror for specific warnings? - J.