diff --git a/lib/libdvben50221/en50221_session.c b/lib/libdvben50221/en50221_session.c
--- a/lib/libdvben50221/en50221_session.c
+++ b/lib/libdvben50221/en50221_session.c
@@ -715,13 +715,13 @@ static void en50221_sl_handle_close_sess
 						     uint8_t connection_id)
 {
 	// check
-	if (data_length < 5) {
+	if (data_length < 4) {
 		print(LOG_LEVEL, ERROR, 1,
 		      "Received data with invalid length from module on slot %02x\n",
 		      slot_id);
 		return;
 	}
-	if (data[0] != 4) {
+	if (data[0] != 3) {
 		print(LOG_LEVEL, ERROR, 1,
 		      "Received data with invalid length from module on slot %02x\n",
 		      slot_id);