Index: src_plugins/export_openems/export_openems.c
===================================================================
--- src_plugins/export_openems/export_openems.c	(revision 32020)
+++ src_plugins/export_openems/export_openems.c	(revision 32021)
@@ -192,6 +192,19 @@
 	return openems_attribute_list;
 }
 
+TODO("remove this once the function is moved and published in core")
+extern const char *pcb_layergrp_thickness_attr(pcb_layergrp_t *grp, const char *namespace);
+
+rnd_coord_t ems_layergrp_thickness(pcb_layergrp_t *grp)
+{
+	rnd_coord_t th;
+	const char *s = pcb_layergrp_thickness_attr(grp, "openems");
+	if (s != NULL)
+		th = rnd_get_value(s, NULL, NULL, NULL);
+	return th;
+}
+
+
 /* Find the openems 0;0 mark, if there is any */
 static void find_origin_bump(void *ctx_, pcb_board_t *pcb, pcb_layer_t *layer, pcb_line_t *line)
 {
Index: src_plugins/export_openems/openems_xml.c
===================================================================
--- src_plugins/export_openems/openems_xml.c	(revision 32020)
+++ src_plugins/export_openems/openems_xml.c	(revision 32021)
@@ -28,10 +28,6 @@
 static double def_end_crit = 1e-05;
 static long def_f_max = 2100000000;
 
-TODO("remove this once the function is moved and published in core")
-extern const char *pcb_layergrp_thickness_attr(pcb_layergrp_t *grp, const char *namespace);
-
-
 static void openems_wr_xml_layergrp_end(wctx_t *ctx)
 {
 	if (ctx->cond_sheet_open) {
@@ -89,15 +85,9 @@
 
 static int openems_wr_xml_outline(wctx_t *ctx, pcb_layergrp_t *g)
 {
-	int n;
 	pcb_any_obj_t *out1;
-	const char *s;
-	rnd_coord_t th = 0;
+	rnd_coord_t th = ems_layergrp_thickness(g);
 
-	s = pcb_layergrp_thickness_attr(g, "openems");
-	if (s != NULL)
-		th = rnd_get_value(s, NULL, NULL, NULL);
-
 	if (th <= 0) {
 		rnd_message(RND_MSG_ERROR, "Substrate thickness is missing or invalid - can't export\n");
 		return -1;