diff --git a/CHANGELOG.markdown b/CHANGELOG.markdown
--- a/CHANGELOG.markdown
+++ b/CHANGELOG.markdown
@@ -1,3 +1,7 @@
+5.6.2 [2021.02.17]
+------------------
+* Add `Semigroup` and `Monoid` instances for `Forget`
+
 5.6.1 [2020.12.31]
 ------------------
 * Add `Functor` instances for `PastroSum`, `CopastroSum`, `Environment`,
diff --git a/profunctors.cabal b/profunctors.cabal
--- a/profunctors.cabal
+++ b/profunctors.cabal
@@ -1,6 +1,6 @@
 name:          profunctors
 category:      Control, Categories
-version:       5.6.1
+version:       5.6.2
 license:       BSD3
 cabal-version: >= 1.10
 license-file:  LICENSE
diff --git a/src/Data/Profunctor/Types.hs b/src/Data/Profunctor/Types.hs
--- a/src/Data/Profunctor/Types.hs
+++ b/src/Data/Profunctor/Types.hs
@@ -41,11 +41,18 @@
 import Data.Distributive
 import Data.Foldable
 import Data.Functor.Contravariant
-import Data.Monoid hiding (Product)
 import Data.Profunctor.Unsafe
 import Data.Traversable
 import Prelude hiding (id,(.))
 
+#if !(MIN_VERSION_base(4,8,0))
+import Data.Monoid (Monoid(..))
+#endif
+
+#if !(MIN_VERSION_base(4,11,0))
+import Data.Semigroup (Semigroup(..))
+#endif
+
 infixr 0 :->
 
 -- | (':->') has a polymorphic kind since @5.6@.
@@ -243,3 +250,21 @@
 instance Contravariant (Forget r a) where
   contramap _ (Forget k) = Forget k
   {-# INLINE contramap #-}
+
+-- | Via @Semigroup r => (a -> r)@
+--
+-- @since 5.6.2
+instance Semigroup r => Semigroup (Forget r a b) where
+  Forget f <> Forget g = Forget (f <> g)
+  {-# INLINE (<>) #-}
+
+-- | Via @Monoid r => (a -> r)@
+--
+-- @since 5.6.2
+instance Monoid r => Monoid (Forget r a b) where
+  mempty = Forget mempty
+  {-# INLINE mempty #-}
+#if !(MIN_VERSION_base(4,11,0))
+  mappend (Forget f) (Forget g) = Forget (mappend f g)
+  {-# INLINE mappend #-}
+#endif