diff --git a/Data/Void.hs b/Data/Void.hs
--- a/Data/Void.hs
+++ b/Data/Void.hs
@@ -11,9 +11,14 @@
 ----------------------------------------------------------------------------
 module Data.Void (Void, absurd) where
 
+import Data.Semigroup (Semigroup(..))
+
 newtype Void = Void Void deriving (Eq,Ord,Show,Read)
 
 -- | Since Void values are logically uninhabited, this witnesses the logical
 -- reasoning tool of 'ex falso quodlibet'.
 absurd :: Void -> a
 absurd (Void a) = absurd a
+
+instance Semigroup Void where
+  a <> _ = a
diff --git a/void.cabal b/void.cabal
--- a/void.cabal
+++ b/void.cabal
@@ -1,6 +1,6 @@
 name:          void
 category:      Data Structures
-version:       0.4
+version:       0.5.0
 license:       BSD3
 cabal-version: >= 1.6
 license-file:  LICENSE
@@ -18,6 +18,6 @@
   location: git://github.com/ekmett/void.git
 
 library
-  build-depends: base >= 3 && < 10
+  build-depends: base >= 3 && < 10, semigroups >= 0.4 && < 0.5
   exposed-modules: Data.Void
   ghc-options: -Wall