diff --git a/Data/Graph/Class.hs b/Data/Graph/Class.hs
--- a/Data/Graph/Class.hs
+++ b/Data/Graph/Class.hs
@@ -116,7 +116,7 @@
   edgeMap = liftEdgeMap
 
 voidMap :: PropertyMap Identity Void a
-voidMap = PropertyMap (Identity . void) $ \_ _ -> Identity voidMap
+voidMap = PropertyMap (Identity . absurd) $ \_ _ -> Identity voidMap
 
 -- | The empty graph
 instance Graph Identity where
diff --git a/graphs.cabal b/graphs.cabal
--- a/graphs.cabal
+++ b/graphs.cabal
@@ -1,6 +1,6 @@
 name:          graphs
 category:      Data Structures
-version:       0.3
+version:       0.3.1
 license:       BSD3
 cabal-version: >= 1.6
 license-file:  LICENSE
@@ -24,7 +24,7 @@
     data-default >= 0.2 && < 0.3,
     transformers >= 0.2.2 && < 0.3,
     containers >= 0.3 && < 0.5,
-    void >= 0.3 && < 0.4
+    void >= 0.4 && < 0.5
 
   exposed-modules:
     Data.Graph.AdjacencyList