diff --git a/generics-sop.cabal b/generics-sop.cabal
--- a/generics-sop.cabal
+++ b/generics-sop.cabal
@@ -1,5 +1,5 @@
 name:                generics-sop
-version:             0.1.0.4
+version:             0.1.1
 synopsis:            Generic Programming using True Sums of Products
 description:
   A library to support the definition of generic functions.
diff --git a/src/Generics/SOP.hs b/src/Generics/SOP.hs
--- a/src/Generics/SOP.hs
+++ b/src/Generics/SOP.hs
@@ -69,9 +69,9 @@
 -- For example,
 --
 -- >>> from (D (C True) 3) :: Rep A
--- > SOP (S (Z (I (C True) :* I 3 :* Nil)))
+-- SOP (S (Z (I (C True) :* I 3 :* Nil)))
 -- >>> to it :: A
--- > D (C True) 3
+-- D (C True) 3
 --
 -- Note that the transformation is shallow: In @D (C True) 3@, the
 -- inner value @C True@ of type @A@ is not affected by the
@@ -153,13 +153,13 @@
 --
 -- >>> let x = G 2.5 'A' False :: B Double
 -- >>> from x
--- > SOP (S (Z (I 2.5 :* I 'A' :* I False :* Nil)))
+-- SOP (S (Z (I 2.5 :* I 'A' :* I False :* Nil)))
 -- >>> hcliftA (Proxy :: Proxy NFData) (\ (I x) -> K (rnf x)) it
--- > SOP (S (Z (K () :* K () :* K () :* Nil)))
+-- SOP (S (Z (K () :* K () :* K () :* Nil)))
 -- >>> hcollapse it
--- > [(),(),()]
+-- [(),(),()]
 -- >>> rnf it
--- > ()
+-- ()
 --
 -- The 'from' call converts into the structural representation.
 -- Via 'hcliftA', we apply 'rnf' to all the components. The result
@@ -176,9 +176,9 @@
 -- class 'Generic'.
 --
 -- >>> grnf (G 2.5 'A' False)
--- > ()
+-- ()
 -- >>> grnf (G 2.5 undefined False)
--- > *** Exception: Prelude.undefined
+-- *** Exception: Prelude.undefined
 --
 -- Note that the type of 'grnf' requires that all components of the
 -- type are in the 'Control.DeepSeq.NFData' class. For a recursive
diff --git a/src/Generics/SOP/Instances.hs b/src/Generics/SOP/Instances.hs
--- a/src/Generics/SOP/Instances.hs
+++ b/src/Generics/SOP/Instances.hs
@@ -67,6 +67,21 @@
 deriveGeneric ''(,,,,,,,,,,,,)
 deriveGeneric ''(,,,,,,,,,,,,,)
 deriveGeneric ''(,,,,,,,,,,,,,,) -- 15
+deriveGeneric ''(,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,) -- 20
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,,,,) -- 25
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,,,,,,,,)
+deriveGeneric ''(,,,,,,,,,,,,,,,,,,,,,,,,,,,,,) -- 30
 deriveGeneric ''[]
 
 -- Other types from base:
diff --git a/src/Generics/SOP/NP.hs b/src/Generics/SOP/NP.hs
--- a/src/Generics/SOP/NP.hs
+++ b/src/Generics/SOP/NP.hs
@@ -122,9 +122,9 @@
 -- /Example:/
 --
 -- >>> pure_NP [] :: NP [] '[Char, Bool]
--- > "" :* [] :* Nil
+-- "" :* [] :* Nil
 -- >>> pure_NP (K 0) :: NP (K Int) '[Double, Int, String]
--- > K 0 :* K 0 :* K 0 :* Nil
+-- K 0 :* K 0 :* K 0 :* Nil
 --
 pure_NP :: forall f xs. SingI xs => (forall a. f a) -> NP f xs
 pure_NP f = case sing :: Sing xs of
@@ -311,7 +311,7 @@
 -- /Example:/
 --
 -- >>> collapse_NP (K 1 :* K 2 :* K 3 :* Nil)
--- > [1,2,3]
+-- [1,2,3]
 --
 collapse_NP  ::              NP  (K a) xs  ->  [a]
 
@@ -320,7 +320,7 @@
 -- /Example:/
 --
 -- >>> collapse_POP (POP ((K 'a' :* Nil) :* (K 'b' :* K 'c' :* Nil) :* Nil) :: POP (K Char) '[ '[(a :: *)], '[b, c] ])
--- > ["a", "bc"]
+-- ["a", "bc"]
 --
 -- (The type signature is only necessary in this case to fix the kind of the type variables.)
 --
@@ -358,7 +358,7 @@
 -- /Example:/
 --
 -- >>> sequence_NP (Just 1 :* Just 2 :* Nil)
--- > Just (I 1 :* I 2 :* Nil)
+-- Just (I 1 :* I 2 :* Nil)
 --
 sequence_NP  :: (SingI xs,  Applicative f) => NP  f xs  -> f (NP  I xs)
 
@@ -367,7 +367,7 @@
 -- /Example:/
 --
 -- >>> sequence_POP (POP ((Just 1 :* Nil) :* (Just 2 :* Just 3 :* Nil) :* Nil))
--- > Just (POP ((I 1 :* Nil) :* ((I 2 :* (I 3 :* Nil)) :* Nil)))
+-- Just (POP ((I 1 :* Nil) :* ((I 2 :* (I 3 :* Nil)) :* Nil)))
 --
 sequence_POP :: (SingI xss, Applicative f) => POP f xss -> f (POP I xss)
 
diff --git a/src/Generics/SOP/NS.hs b/src/Generics/SOP/NS.hs
--- a/src/Generics/SOP/NS.hs
+++ b/src/Generics/SOP/NS.hs
@@ -152,7 +152,7 @@
 -- /Example:/
 --
 -- >>> apInjs_NP (I 'x' :* I True :* I 2 :* Nil)
--- > [Z (I 'x'), S (Z (I True)), S (S (Z (I 2)))]
+-- [Z (I 'x'), S (Z (I True)), S (S (Z (I 2)))]
 --
 apInjs_NP  :: SingI xs  => NP  f xs  -> [NS  f xs]
 apInjs_NP  = hcollapse . hap injections
@@ -167,7 +167,7 @@
 -- /Example:/
 --
 -- >>> apInjs_POP (POP ((I 'x' :* Nil) :* (I True :* I 2 :* Nil) :* Nil))
--- > [SOP (Z (I 'x' :* Nil)),SOP (S (Z (I True :* (I 2 :* Nil))))]
+-- [SOP (Z (I 'x' :* Nil)),SOP (S (Z (I True :* (I 2 :* Nil))))]
 --
 apInjs_POP :: SingI xss => POP f xss -> [SOP f xss]
 apInjs_POP = map SOP . apInjs_NP . unPOP
diff --git a/src/Generics/SOP/Sing.hs b/src/Generics/SOP/Sing.hs
--- a/src/Generics/SOP/Sing.hs
+++ b/src/Generics/SOP/Sing.hs
@@ -83,7 +83,7 @@
 -- of type-level lists (esp because of https://ghc.haskell.org/trac/ghc/ticket/9108)
 data Shape :: [k] -> * where
   ShapeNil  :: Shape '[]
-  ShapeCons :: SingI xs => Shape xs -> Shape (x ': xs)
+  ShapeCons :: (SingI x, SingI xs) => Shape xs -> Shape (x ': xs)
 
 deriving instance Show (Shape xs)
 deriving instance Eq   (Shape xs)
diff --git a/src/Generics/SOP/Universe.hs b/src/Generics/SOP/Universe.hs
--- a/src/Generics/SOP/Universe.hs
+++ b/src/Generics/SOP/Universe.hs
@@ -6,6 +6,7 @@
 import qualified GHC.Generics as GHC
 
 import Generics.SOP.BasicFunctors
+import Generics.SOP.Constraint
 import Generics.SOP.NS
 import Generics.SOP.Sing
 import Generics.SOP.GGP
@@ -89,7 +90,7 @@
 --
 -- still holds.
 --
-class SingI (Code a) => Generic (a :: *) where
+class (SingI (Code a), All SingI (Code a)) => Generic (a :: *) where
   -- | The code of a datatype.
   --
   -- This is a list of lists of its components. The outer list contains