@@ -587,7 +587,12 @@ instance HasTrie a => Monad ((:->:) a) where
587587
588588instance (HasTrie a, Monoid b) => Monoid (a :->: b) where
589589 mempty = trie mempty
590+#if !MIN_VERSION_base(4,11,0)
590591 mappend = inTrie2 mappend
592+#else
593+instance (HasTrie a, Semigroup b) => Semigroup (a :->: b) where
594+ (<>) = inTrie2 (<>)
595+#endif
591596
592597instance HasTrie a => Functor ((:->:) a) where
593598 fmap f = inTrie (fmap f)