diff --git a/Data/Universe.hs b/Data/Universe.hs
--- a/Data/Universe.hs
+++ b/Data/Universe.hs
@@ -1,4 +1,7 @@
-{-# LANGUAGE FlexibleContexts, TypeFamilies #-}
+{-# LANGUAGE CPP, FlexibleContexts, TypeFamilies #-}
+#ifdef DEFAULT_SIGNATURES
+{-# LANGUAGE DefaultSignatures #-}
+#endif
 module Data.Universe
 	( -- | Bottoms are ignored for this entire module: only fully-defined inhabitants are considered inhabitants.
 	  Universe(..)
@@ -11,7 +14,6 @@
 import Data.Monoid
 import Data.Ratio
 import Data.Universe.Helpers
-import Data.Universe.Class
 import Data.Void
 import Data.Word
 
@@ -24,6 +26,25 @@
 import Data.Functor.Representable
 import Data.Key (Key)
 import qualified Data.Functor.Product as Functor
+
+-- | Creating an instance of this class is a declaration that your type is
+-- recursively enumerable (and that 'universe' is that enumeration). In
+-- particular, you promise that any finite inhabitant has a finite index in
+-- 'universe', and that no inhabitant appears at two different finite indices.
+class Universe a where
+	universe :: [a]
+#ifdef DEFAULT_SIGNATURES
+	default universe :: (Enum a, Bounded a) => [a]
+	universe = universeDef
+#endif
+
+-- | Creating an instance of this class is a declaration that your 'universe'
+-- eventually ends. Minimal definition: no methods defined. By default,
+-- @universeF = universe@, but for some types (like 'Either') the 'universeF'
+-- method may have a more intuitive ordering.
+class Universe a => Finite a where
+	universeF :: [a]
+	universeF = universe
 
 instance Universe ()       where universe = universeDef
 instance Universe Bool     where universe = universeDef
diff --git a/Data/Universe/Helpers.hs b/Data/Universe/Helpers.hs
--- a/Data/Universe/Helpers.hs
+++ b/Data/Universe/Helpers.hs
@@ -7,9 +7,6 @@
 
 import Data.List
 
--- WHEN EDITING THIS DEFINITION:
--- edit ../../defsigs/Data/Universe/Class.hs:universe in tandem!
-
 -- | For many types, the 'universe' should be @[minBound .. maxBound]@;
 -- 'universeDef' makes it easy to make such types an instance of 'Universe' via
 -- the snippet
diff --git a/defsigs/Data/Universe/Class.hs b/defsigs/Data/Universe/Class.hs
deleted file mode 100644
--- a/defsigs/Data/Universe/Class.hs
+++ /dev/null
@@ -1,23 +0,0 @@
--- WHEN EDITING THIS FILE:
--- edit ../../nodefsigs/Data/Universe.hs in tandem!
-{-# LANGUAGE DefaultSignatures #-}
-module Data.Universe.Class where
-
--- | Creating an instance of this class is a declaration that your type is
--- recursively enumerable (and that 'universe' is that enumeration). In
--- particular, you promise that any finite inhabitant has a finite index in
--- 'universe', and that no inhabitant appears at two different finite indices.
-class Universe a where
-	universe :: [a]
-	default universe :: (Enum a, Bounded a) => [a]
-	-- WHEN EDITING THIS DEFINITION:
-	-- edit ../../Data/Universe/Helpers.hs:universeDef in tandem!
-	universe = [minBound .. maxBound]
-
--- | Creating an instance of this class is a declaration that your 'universe'
--- eventually ends. Minimal definition: no methods defined. By default,
--- @universeF = universe@, but for some types (like 'Either') the 'universeF'
--- method may have a more intuitive ordering.
-class Universe a => Finite a where
-	universeF :: [a]
-	universeF = universe
diff --git a/nodefsigs/Data/Universe/Class.hs b/nodefsigs/Data/Universe/Class.hs
deleted file mode 100644
--- a/nodefsigs/Data/Universe/Class.hs
+++ /dev/null
@@ -1,17 +0,0 @@
--- WHEN EDITING THIS FILE:
--- edit ../../nodefsigs/Data/Universe.hs in tandem!
-module Data.Universe.Class where
-
--- | Creating an instance of this class is a declaration that your type is
--- recursively enumerable (and that 'universe' is that enumeration). In
--- particular, you promise that any finite inhabitant has a finite index in
--- 'universe', and that no inhabitant appears at two different finite indices.
-class Universe a where universe :: [a]
-
--- | Creating an instance of this class is a declaration that your 'universe'
--- eventually ends. Minimal definition: no methods defined. By default,
--- @universeF = universe@, but for some types (like 'Either') the 'universeF'
--- method may have a more intuitive ordering.
-class Universe a => Finite a where
-	universeF :: [a]
-	universeF = universe
diff --git a/universe.cabal b/universe.cabal
--- a/universe.cabal
+++ b/universe.cabal
@@ -1,5 +1,5 @@
 name:                universe
-version:             0.4
+version:             0.4.0.1
 synopsis:            Classes for types where we know all the values
 description:         A small package, in the spirit of data-default, which allows the munging of finite and recursively enumerable types
 license:             BSD3
@@ -9,8 +9,6 @@
 copyright:           2013 Daniel Wagner
 category:            Data
 build-type:          Simple
-extra-source-files:    defsigs/Data/Universe/Class.hs,
-                     nodefsigs/Data/Universe/Class.hs
 cabal-version:       >=1.8
 source-repository head
     type:            git
@@ -18,7 +16,7 @@
 source-repository this
     type:            git
     location:        https://github.com/dmwit/universe
-    tag:             0.3
+    tag:             0.4.0.1
 
 library
   exposed-modules:     Data.Universe,
@@ -29,12 +27,8 @@
                        Data.Universe.Instances.Read,
                        Data.Universe.Instances.Show,
                        Data.Universe.Instances.Traversable
-  other-modules:       Data.Universe.Class
-  hs-source-dirs:      .
   if impl(ghc >= 7.4)
-    hs-source-dirs:      defsigs
-  else
-    hs-source-dirs:    nodefsigs
+    cpp-options:       -DDEFAULT_SIGNATURES
   build-depends:       base                   >=4   && <5  ,
                        comonad-transformers   >=0.1 && <3.1,
                        containers             >=0.1 && <1  ,