Index: trunk/src/obj_line_drcenf.c
===================================================================
--- trunk/src/obj_line_drcenf.c	(revision 6135)
+++ trunk/src/obj_line_drcenf.c	(revision 6136)
@@ -476,11 +476,14 @@
 	double r1, r2;
 
 	/* Silence a bogus compiler warning by storing this in a variable */
-	int layer_idx = INDEXOFCURRENT;
+	pcb_layer_id_t layer_idx = INDEXOFCURRENT;
 
-	if (pcb_gui->mod1_is_pressed() || pcb_gui->control_is_pressed() || PCB->RatDraw || layer_idx >= pcb_max_copper_layer)
+	if (pcb_gui->mod1_is_pressed() || pcb_gui->control_is_pressed() || PCB->RatDraw)
 		return;
 
+	if (!(pcb_layer_flags(layer_idx) & PCB_LYT_COPPER))
+		return;
+
 	rs.X = r45.X = pcb_crosshair.X;
 	rs.Y = r45.Y = pcb_crosshair.Y;