Index: obj_arc.c
===================================================================
--- obj_arc.c	(revision 19694)
+++ obj_arc.c	(revision 19695)
@@ -760,6 +760,7 @@
 	if (sth != 1.0)
 		arc->Thickness = pcb_round((double)arc->Thickness * sth);
 
+	pcb_arc_bbox(arc);
 	pcb_arc_post(arc);
 }