Documentation for hGetChar et.al. [1] does not mention the exception for invalid byte sequences in the current encoding. It seems it throws an exception called "invalid argument": IO> h <- IO.openFile "/tmp/invalid" IO.ReadMode IO> IO.hGetChar h *** Exception: /tmp/invalid: hGetChar: invalid argument (invalid byte sequence) https://hackage.haskell.org/package/base-4.14.0.0/docs/System-IO.html#v:hGet...