diff --git a/CHANGES b/CHANGES
--- a/CHANGES
+++ b/CHANGES
@@ -1,3 +1,11 @@
+0.4.0.1    10 April 2018
+
+  * bug fix in 'structureType' function (https://github.com/byorgey/species/issues/3)
+
+0.4-r1     12 October 2017
+
+  * Allow base-4.10 (GHC 8.2)
+
 0.4         9 August 2016
 
   * Add support for GHC 8.0.1.  Unfortunately, the price to pay for this is
diff --git a/Math/Combinatorics/Species/Enumerate.hs b/Math/Combinatorics/Species/Enumerate.hs
--- a/Math/Combinatorics/Species/Enumerate.hs
+++ b/Math/Combinatorics/Species/Enumerate.hs
@@ -203,8 +203,7 @@
   where extractType :: forall s. Typeable s => TSpeciesAST s -> TypeRep
         extractType _ = typeOf1 (undefined :: s ())
 
--- | Show a 'TypeRep' while stripping off qualifier portions of 'TyCon'
---   names.  This is essentially copied and pasted from the
+-- | Show a 'TypeRep'.  This is essentially copied and pasted from the
 --   "Data.Typeable" source, with a number of cases taken out that we
 --   don't care about (special cases for @(->)@, tuples, etc.).
 showStructureType :: TypeRep -> String
@@ -212,21 +211,26 @@
   where showsPrecST :: Int -> TypeRep -> ShowS
         showsPrecST p t =
           case splitTyConApp t of
-            (tycon, [])   -> showString (dropQuals $ tyConName tycon)
+            (tycon, [])   -> showString (tyConName tycon)
             (tycon, [x])  | tyConName tycon == "[]"
                               -> showChar '[' . showsPrecST 11 x . showChar ']'
-            (tycon, args) -> showParen (p > 9)
-                               $ showString (dropQuals $ tyConName tycon)
-                               . showChar ' '
-                               . showArgsST args
+            (tycon, args) -> showParen (p > 9) $
+              case (tyConName tycon, args) of
+                (':':_, [x,y]) -> showsPrecST 10 x . showChar ' '
+                                . showString (tyConName tycon)
+                                . showChar ' '
+                                . showsPrecST 10 y
+                (':':_, _)     -> showChar '(' . showString (tyConName tycon)
+                                . showChar ')' . showChar ' '
+                                . showArgsST args
+                _              -> showString (tyConName tycon)
+                                . showChar ' '
+                                . showArgsST args
 
         showArgsST :: [TypeRep] -> ShowS
         showArgsST []     = id
         showArgsST [t]    = showsPrecST 10 t
         showArgsST (t:ts) = showsPrecST 10 t . showChar ' ' . showArgsST ts
-
-        dropQuals :: String -> String
-        dropQuals = reverse . takeWhile (/= '.') . reverse
 
 -- | 'enumerateE' is a variant of 'enumerate'' which takes an
 --   (existentially quantified) typed AST and returns a list of
diff --git a/species.cabal b/species.cabal
--- a/species.cabal
+++ b/species.cabal
@@ -1,5 +1,5 @@
 name:           species
-version:        0.4
+version:        0.4.0.1
 license:        BSD3
 license-file:   LICENSE
 build-type:     Simple
@@ -20,7 +20,7 @@
   location: https://github.com/byorgey/species
 
 Library
-  build-depends: base >= 4.7 && < 4.10,
+  build-depends: base >= 4.7 && < 4.11,
                  numeric-prelude >= 0.3 && < 0.5,
                  np-extras >= 0.3 && < 0.4,
                  containers >= 0.2 && < 0.6,