diff --git a/plugins/udevng.c b/plugins/udevng.c
index e8b800c1..aa28bcb8 100644
--- a/plugins/udevng.c
+++ b/plugins/udevng.c
@@ -214,12 +214,20 @@ static gboolean setup_gobi(struct modem_info *modem)
 			net = info->devnode;
 		else if (g_strcmp0(info->subsystem, "tty") == 0) {
 			if (g_strcmp0(info->interface, "255/255/255") == 0) {
-				if (g_strcmp0(info->number, "01") == 0)
-					diag = info->devnode;
+				if (g_strcmp0(info->number, "00") == 0)
+					diag = info->devnode; /* ec20 */
+				else if (g_strcmp0(info->number, "01") == 0)
+					diag = info->devnode; /* gobi */
 				else if (g_strcmp0(info->number, "02") == 0)
-					mdm = info->devnode;
+					mdm = info->devnode; /* gobi */
 				else if (g_strcmp0(info->number, "03") == 0)
-					gps = info->devnode;
+					gps = info->devnode; /* gobi */
+			} else if (g_strcmp0(info->interface, "255/0/0") == 0) {
+				if (g_strcmp0(info->number, "01") == 0)
+					gps = info->devnode; /* ec20 */
+				if (g_strcmp0(info->number, "02") == 0)
+					mdm = info->devnode; /* ec20 */
+				/* ignore the 3rd device second AT/mdm iface */
 			}
 		}
 	}