--- a/src/HOL/Quickcheck_Narrowing.thy	Fri Jan 18 19:48:04 2019 -0500
+++ b/src/HOL/Quickcheck_Narrowing.thy	Sat Jan 19 07:19:16 2019 +0000
@@ -15,6 +15,8 @@
 
 code_printing
   code_module Typerep \<rightharpoonup> (Haskell_Quickcheck) \<open>
+module Typerep(Typerep(..)) where
+
 data Typerep = Typerep String [Typerep]
 \<close> for type_constructor typerep constant Typerep.Typerep
 | type_constructor typerep \<rightharpoonup> (Haskell_Quickcheck) "Typerep.Typerep"