[Haskell-beginners] instance

Hi, data TisanInteger = Tisan Integer instance Eq (Tisan Integer) where (Tisan v) == (Tisan v') = v == v' prelude> Instance_testen.hs:7:14: error:     Not in scope: type constructor or class ‘Tisan’     A data constructor of that name is in scope; did you mean DataKinds?   | 7 | instance Eq (Tisan Integer) where (Tisan v) == (Tisan v') = v == v'   |              ^^^^^ [1 of 1] Compiling Main             ( Instance_testen.hs, interpreted ) Failed, no modules loaded. what am i doing wrong? best,