diff --git a/Math/Manifold/Core/Types/Internal.hs b/Math/Manifold/Core/Types/Internal.hs
--- a/Math/Manifold/Core/Types/Internal.hs
+++ b/Math/Manifold/Core/Types/Internal.hs
@@ -10,6 +10,7 @@
 -- Several low-dimensional manifolds, represented in some simple way as Haskell
 -- data types. All these are in the 'PseudoAffine' class.
 -- 
+{-# LANGUAGE DeriveGeneric    #-}
 
 
 module Math.Manifold.Core.Types.Internal where
@@ -18,29 +19,31 @@
 
 import Data.Fixed (mod')
 
+import GHC.Generics
 
+
 -- | The zero-dimensional sphere is actually just two points. Implementation might
 --   therefore change to @ℝ⁰ 'Control.Category.Constrained.+' ℝ⁰@: the disjoint sum of two
 --   single-point spaces.
-data S⁰ = PositiveHalfSphere | NegativeHalfSphere deriving(Eq, Show)
+data S⁰ = PositiveHalfSphere | NegativeHalfSphere deriving(Eq, Show, Generic)
 
-data ℝP⁰ = ℝPZero deriving (Eq, Show)
+data ℝP⁰ = ℝPZero deriving (Eq, Show, Generic)
 
 -- | The unit circle.
 newtype S¹ = S¹Polar { φParamS¹ :: Double -- ^ Must be in range @[-π, π[@.
-                     } deriving (Show)
+                     } deriving (Show, Generic)
 
 instance Eq S¹ where
   S¹Polar φ == S¹Polar φ' = φ `mod'` (2*pi) == φ' `mod'` (2*pi)
 
 
 newtype ℝP¹ = HemisphereℝP¹Polar { φParamℝP¹ :: Double -- ^ Range @[-π\/2,π\/2[@.
-                                 } deriving (Show)
+                                 } deriving (Show, Generic)
 
 -- | The ordinary unit sphere.
 data S² = S²Polar { ϑParamS² :: !Double -- ^ Range @[0, π[@.
                   , φParamS² :: !Double -- ^ Range @[-π, π[@.
-                  } deriving (Show)
+                  } deriving (Show, Generic)
 
 instance Eq S² where
   S²Polar θ φ == S²Polar θ' φ'
@@ -54,7 +57,7 @@
 --   passes through the hemisphere.
 data ℝP² = HemisphereℝP²Polar { ϑParamℝP² :: !Double -- ^ Range @[0, π/2]@.
                               , φParamℝP² :: !Double -- ^ Range @[-π, π[@.
-                              } deriving (Show)
+                              } deriving (Show, Generic)
 
 
 -- | The standard, closed unit disk. Homeomorphic to the cone over 'S¹', but not in the
@@ -62,7 +65,7 @@
 --   the almost identical ADT definition, to the projective space 'ℝP²'!)
 data D² = D²Polar { rParamD² :: !Double -- ^ Range @[0, 1]@.
                   , φParamD² :: !Double -- ^ Range @[-π, π[@.
-                  } deriving (Show)
+                  } deriving (Show, Generic)
 
 -- | A (closed) cone over a space @x@ is the product of @x@ with the closed interval 'D¹'
 --   of “heights”,
@@ -72,7 +75,7 @@
 --   special case @x = 'S¹'@.
 data CD¹ x = CD¹ { hParamCD¹ :: !Double -- ^ Range @[0, 1]@
                  , pParamCD¹ :: !x      -- ^ Irrelevant at @h = 0@.
-                 } deriving (Show)
+                 } deriving (Show, Generic)
 
 
 -- | An open cone is homeomorphic to a closed cone without the “lid”,
@@ -81,12 +84,12 @@
 --   more natural to express it as the entire real ray, hence the name.
 data Cℝay x = Cℝay { hParamCℝay :: !Double -- ^ Range @[0, ∞[@
                    , pParamCℝay :: !x      -- ^ Irrelevant at @h = 0@.
-                   } deriving (Show)
+                   } deriving (Show, Generic)
 
 -- | The “one-dimensional disk” – really just the line segment between
 --   the two points -1 and 1 of 'S⁰', i.e. this is simply a closed interval.
 newtype D¹ = D¹ { xParamD¹ :: Double -- ^ Range @[-1, 1]@.
-                } deriving (Show)
+                } deriving (Show, Generic)
 
 type ℝ = Double
 type ℝ⁰ = ZeroDim ℝ
diff --git a/manifolds-core.cabal b/manifolds-core.cabal
--- a/manifolds-core.cabal
+++ b/manifolds-core.cabal
@@ -2,7 +2,7 @@
 -- documentation, see http://haskell.org/cabal/users-guide/
 
 name:                manifolds-core
-version:             0.5.0.1
+version:             0.5.0.2
 synopsis:            The basic classes for the manifolds hierarchy.
 description:         The basic classes for the
                      <http://hackage.haskell.org/package/manifolds manifolds> hierarchy.