Index: undo_old.c
===================================================================
--- undo_old.c	(revision 10984)
+++ undo_old.c	(revision 10985)
@@ -1118,6 +1118,7 @@
 /* ---------------------------------------------------------------------------
  * adds an object to the list of objects with flags changed
  */
+extern unsigned long pcb_obj_type2oldtype(pcb_objtype_t type);
 void pcb_undo_add_obj_to_flag(void *obj_)
 {
 	UndoListTypePtr undo;