--- compiler/inst_match.m~	2011-04-04 22:03:49.489592747 -0400
+++ compiler/inst_match.m	2011-04-04 22:03:49.489592747 -0400
@@ -1048,7 +1048,7 @@
         % We can only do this check if the type is known.
         bound_inst_list_is_complete_for_type(set.init, ModuleInfo, ListB, Type)
     ;
-        true
+        MaybeType = no
         % XXX enabling the check for bound_inst_list_is_complete
         % for type makes the mode checker too conservative in
         % the absence of alias tracking, so we currently always