diff --git a/drivers/mehfet.c b/drivers/mehfet.c
index 05eb874..9150511 100644
--- a/drivers/mehfet.c
+++ b/drivers/mehfet.c
@@ -553,11 +553,11 @@ static void mehfet_destroy(device_t dev_base) {
 	printc_dbg("mehfet: releasing device & disconnecting\n");
 #endif
 
-	jtag_release_device(&dev->jtag, 0xfffe); // 0xfffe=reset address : POR
-
-	mehfet_cmd_disconnect(dev->trans);
-
 	if (dev->trans) {
+		jtag_release_device(&dev->jtag, 0xfffe); // 0xfffe=reset address : POR
+
+		mehfet_cmd_disconnect(dev->trans);
+
 		dev->trans->ops->destroy(dev->trans);
 		dev->trans = NULL;
 	}
diff --git a/transport/mehfet_xport.c b/transport/mehfet_xport.c
index 5bb3470..42f650a 100644
--- a/transport/mehfet_xport.c
+++ b/transport/mehfet_xport.c
@@ -241,6 +241,8 @@ transport_t mehfet_transport_open(const char *devpath,
 		dev = usbutil_find_by_id(*vendor, *product, requested_serial);
 
 	if (!dev) {
+		printc_err("mehfet: no USB device found.%s\n",
+			vendor ? "" : " (Did you forget to specify a VID:PID?)");
 		free(tr);
 		return NULL;
 	}
@@ -248,7 +250,7 @@ transport_t mehfet_transport_open(const char *devpath,
 	tr->buf_size = 64; // initial conservative value, will get updated later
 
 	if (open_device(tr, dev) < 0) {
-		printc_err("ftdi: failed to open device\n");
+		printc_err("mehfet: failed to open device\n");
 		free(tr);
 		return NULL;
 	}