diff --git a/CHANGELOG.md b/CHANGELOG.md
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,6 +1,11 @@
+1.3.2
+
+* Compatibility with `Semigroup` becoming a super-class of `Monoid`
+* Fix `asin` for `Fold`
+
 1.3.1
 
-* BUG FIX: `asin` now correctly delegates to `fmap asin` and not `fmap sin`
+* Fix `asin` for `FoldM`
 
 1.3.0
 
diff --git a/README.md b/README.md
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-# `foldl` v1.3.1
+# `foldl` v1.3.2
 
 Use this `foldl` library when you want to compute multiple folds over a
 collection in one pass over the data without space leaks.
diff --git a/foldl.cabal b/foldl.cabal
--- a/foldl.cabal
+++ b/foldl.cabal
@@ -1,5 +1,5 @@
 Name: foldl
-Version: 1.3.1
+Version: 1.3.2
 Cabal-Version: >=1.8.0.2
 Build-Type: Simple
 License: BSD3
@@ -36,6 +36,7 @@
         unordered-containers        < 0.3 ,
         hashable                    < 1.3 ,
         contravariant               < 1.5 ,
+        semigroups   >= 0.17     && < 1.19,
         profunctors                 < 5.3 ,
         comonad      >= 4.0      && < 6   ,
         vector-builder              < 0.4
diff --git a/src/Control/Foldl.hs b/src/Control/Foldl.hs
--- a/src/Control/Foldl.hs
+++ b/src/Control/Foldl.hs
@@ -143,7 +143,8 @@
 import Data.Foldable (Foldable)
 import Data.Functor.Identity (Identity, runIdentity)
 import Data.Functor.Contravariant (Contravariant(..))
-import Data.Monoid
+import Data.Monoid hiding ((<>))
+import Data.Semigroup (Semigroup(..))
 import Data.Profunctor
 import Data.Sequence ((|>))
 import Data.Vector.Generic (Vector, Mutable)
@@ -222,11 +223,15 @@
         in  Fold step begin done
     {-# INLINE (<*>) #-}
 
+instance Monoid b => Semigroup (Fold a b) where
+    (<>) = liftA2 mappend
+    {-# INLINE (<>) #-}
+
 instance Monoid b => Monoid (Fold a b) where
     mempty = pure mempty
     {-# INLINE mempty #-}
 
-    mappend = liftA2 mappend
+    mappend = (<>)
     {-# INLINE mappend #-}
 
 instance Num b => Num (Fold a b) where
@@ -283,7 +288,7 @@
     cos = fmap cos
     {-# INLINE cos #-}
 
-    asin = fmap sin
+    asin = fmap asin
     {-# INLINE asin #-}
 
     atan = fmap atan
@@ -357,6 +362,10 @@
     rmap = fmap
     lmap = premapM
 
+instance (Monoid b, Monad m) => Semigroup (FoldM m a b) where
+    (<>) = liftA2 mappend
+    {-# INLINE (<>) #-}
+
 instance (Monoid b, Monad m) => Monoid (FoldM m a b) where
     mempty = pure mempty
     {-# INLINE mempty #-}
@@ -1156,11 +1165,15 @@
 -}
 newtype EndoM m a = EndoM { appEndoM :: a -> m a }
 
+instance Monad m => Semigroup (EndoM m a) where
+    (EndoM f) <> (EndoM g) = EndoM (f <=< g)
+    {-# INLINE (<>) #-}
+
 instance Monad m => Monoid (EndoM m a) where
     mempty = EndoM return
     {-# INLINE mempty #-}
 
-    mappend (EndoM f) (EndoM g) = EndoM (f <=< g)
+    mappend = (<>)
     {-# INLINE mappend #-}
 
 {-| A Handler for the upstream input of `FoldM`