Index: renumber.c
===================================================================
--- renumber.c	(revision 23713)
+++ renumber.c	(revision 23714)
@@ -92,7 +92,7 @@
 		name = pcb_gui->fileselect("Save Renumber Annotation File As ...",
 													 "Choose a file to record the renumbering to.\n"
 														 "This file may be used to back annotate the\n"
-														 "change to the schematics.\n", default_file, ".eco", "eco", 0, NULL);
+														 "change to the schematics.\n", default_file, ".eco", NULL, "eco", 0, NULL);
 
 		free_name = pcb_true;
 	}