diff --git a/creatur.cabal b/creatur.cabal
--- a/creatur.cabal
+++ b/creatur.cabal
@@ -1,5 +1,5 @@
 Name:              creatur
-Version:           5.3.0
+Version:           5.3.1
 Stability:         experimental
 Synopsis:          Framework for artificial life experiments.
 Description:       A software framework for automating experiments
@@ -36,7 +36,7 @@
 source-repository this
   type:     git
   location: https://github.com/mhwombat/creatur.git
-  tag:      5.3.0
+  tag:      5.3.1
 
 library
   GHC-Options:      -Wall -fno-warn-orphans
@@ -107,7 +107,7 @@
                     test-framework ==0.8.*,
                     test-framework-hunit ==0.3.*,
                     test-framework-quickcheck2 ==0.3.*,
-                    QuickCheck ==2.6.*
+                    QuickCheck ==2.7.*
   Other-modules:    ALife.Creatur.UtilQC
                     ALife.Creatur.CounterQC
                     ALife.Creatur.Database.CachedFileSystemQC
diff --git a/src/ALife/Creatur/Universe.hs b/src/ALife/Creatur/Universe.hs
--- a/src/ALife/Creatur/Universe.hs
+++ b/src/ALife/Creatur/Universe.hs
@@ -16,6 +16,7 @@
     -- * Constructors
     Universe(..),
     SimpleUniverse,
+    CachedUniverse,
     mkSimpleUniverse,
     mkCachedUniverse,
     -- * Clock