diff -r 39be3c7e643a -r e6091328718f src/HOL/Tools/inductive_package.ML
--- a/src/HOL/Tools/inductive_package.ML	Tue Apr 22 08:33:21 2008 +0200
+++ b/src/HOL/Tools/inductive_package.ML	Tue Apr 22 08:33:23 2008 +0200
@@ -822,7 +822,7 @@
             member (op =) ps t then I else insert (op =) v
         | _ => I) r []), r);
 
-    val intros = map (apsnd (close_rule #> expand)) pre_intros;
+    val intros = map (apsnd (Syntax.check_term lthy #> close_rule #> expand)) pre_intros;
     val preds = map (fn ((c, _), mx) => (c, mx)) cnames_syn';
   in
     lthy