diff -r 81bddc4832e6 -r bacfb7c45d81 src/HOL/Tools/choice_specification.ML
--- a/src/HOL/Tools/choice_specification.ML	Tue Jul 28 21:31:16 2015 +0200
+++ b/src/HOL/Tools/choice_specification.ML	Tue Jul 28 21:47:03 2015 +0200
@@ -178,7 +178,7 @@
           else ()
       in
         arg
-        |> apsnd Thm.unvarify_global
+        |> apsnd (Thm.unvarify_global thy)
         |> process_all (zip3 alt_names rew_imps frees)
       end