diff --git a/monoidal-containers.cabal b/monoidal-containers.cabal
--- a/monoidal-containers.cabal
+++ b/monoidal-containers.cabal
@@ -1,5 +1,5 @@
 name:                monoidal-containers
-version:             0.1.2.3
+version:             0.1.2.4
 synopsis:            Containers with monoidal accumulation
 description:         Containers with monoidal accumulation
 homepage:            http://github.com/bgamari/monoidal-containers
@@ -24,7 +24,7 @@
                        GeneralizedNewtypeDeriving,
                        DeriveTraversable,
                        DeriveDataTypeable
-  build-depends:       base >=4.7 && <4.9,
+  build-depends:       base >=4.7 && <4.10,
                        deepseq >=1.3 && <1.5,
                        containers >=0.5 && <0.6,
                        unordered-containers >= 0.2 && < 0.3,
diff --git a/src/Data/Map/Monoidal.hs b/src/Data/Map/Monoidal.hs
--- a/src/Data/Map/Monoidal.hs
+++ b/src/Data/Map/Monoidal.hs
@@ -142,11 +142,10 @@
 delete k = _Wrapping' MM %~ M.delete k
 {-# INLINE delete #-}
 
--- | /O(n)/.
--- Return all elements of the map in the ascending order of their keys.
--- Subject to list fusion.
+-- | /O(n)/. Return all elements of the map in the ascending order of their
+-- keys. Subject to list fusion.
 elems :: MonoidalMap k a -> [a]
-elems = M.elems . unpack      
+elems = M.elems . unpack
 {-# INLINE elems #-}
 
 -- | /O(n)/. Return all keys of the map in ascending order. Subject to list