Index: obj_arc.c
===================================================================
--- obj_arc.c	(revision 19703)
+++ obj_arc.c	(revision 19704)
@@ -745,8 +745,11 @@
 
 void pcb_arc_scale(pcb_arc_t *arc, double sx, double sy, double sth)
 {
-	pcb_arc_pre(arc);
+	int onbrd = (arc->parent.layer != NULL) && (!arc->parent.layer->is_bound);
 
+	if (onbrd)
+		pcb_arc_pre(arc);
+
 	if (sx != 1.0) {
 		arc->X = pcb_round((double)arc->X * sx);
 		arc->Width = pcb_round((double)arc->Width * sx);
@@ -761,7 +764,8 @@
 		arc->Thickness = pcb_round((double)arc->Thickness * sth);
 
 	pcb_arc_bbox(arc);
-	pcb_arc_post(arc);
+	if (onbrd)
+		pcb_arc_post(arc);
 }
 
 /* rotates an arc */