diff --git a/Data/Semigroup.hs b/Data/Semigroup.hs
--- a/Data/Semigroup.hs
+++ b/Data/Semigroup.hs
@@ -61,6 +61,10 @@
     go b (c:cs) = b <> go c cs
     go b []     = b
 
+instance Semigroup () where
+  _ <> _ = ()
+  sconcat _ = ()
+
 instance Semigroup b => Semigroup (a -> b) where
   f <> g = \a -> f a <> g a
 
diff --git a/semigroups.cabal b/semigroups.cabal
--- a/semigroups.cabal
+++ b/semigroups.cabal
@@ -1,6 +1,6 @@
 name:          semigroups
 category:      Algebra, Data, Data Structures, Math
-version:       0.6
+version:       0.6.1
 license:       BSD3
 cabal-version: >= 1.6
 license-file:  LICENSE