diff -r 74920496ab71 -r 08f3491c50bf src/HOL/Tools/Nitpick/nitpick.ML
--- a/src/HOL/Tools/Nitpick/nitpick.ML	Tue Sep 03 18:21:43 2013 +0200
+++ b/src/HOL/Tools/Nitpick/nitpick.ML	Tue Sep 03 19:58:00 2013 +0200
@@ -456,7 +456,7 @@
        provide a hint to the user. *)
     fun is_struct_induct_step (name, (Rule_Cases.Case {fixes, assumes, ...}, _)) =
       not (null fixes) andalso
-      exists (String.isSuffix ".hyps" o fst) assumes andalso
+      exists (String.isSuffix ".hyps" o Name_Space.full_name Name_Space.default_naming o fst) assumes andalso
       exists (exists (curry (op =) name o shortest_name o fst)
               o datatype_constrs hol_ctxt) deep_dataTs
     val likely_in_struct_induct_step =