No instance for (Semigroup FormEncType)

[cimmanon]

In base 4.11, Semigroup was made a superclass of Monoid, with mappend belonging to Semigroup. This results in the following error:

src/Text/Digestive/Form/Encoding.hs:42:10: error:
    * No instance for (Semigroup FormEncType)
        arising from the superclasses of an instance declaration
    * In the instance declaration for `Monoid FormEncType'
   |
42 | instance Monoid FormEncType where
   |          ^^^^^^^^^^^^^^^^^^