diff --git a/include/osmocom/gsm/protocol/gsm_49_031.h b/include/osmocom/gsm/protocol/gsm_49_031.h
new file mode 100644
index 0000000..b44a07e
--- /dev/null
+++ b/include/osmocom/gsm/protocol/gsm_49_031.h
@@ -0,0 +1,61 @@
+/*! \defgroup bssmap_le 3GPP TS 49.031 BSSMAP-LE.
+ *  @{
+ *  \file gsm_49_031.h
+ */
+/*
+ * (C) 2020 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de>
+ * All Rights Reserved
+ *
+ * Author: Neels Hofmeyr <neels@hofmeyr.de>
+ *
+ * SPDX-License-Identifier: GPL-2.0+
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ */
+#pragma once
+
+#include <stdint.h>
+#include <stdbool.h>
+
+/*! 3GPP TS 49.031 10.13 LCS Cause, also in 3GPP TS 48.008 3.2.2.66, which simply refers to the former. */
+enum lcs_cause {
+	LCS_CAUSE_UNSPECIFIED = 0,
+	LCS_CAUSE_SYSTEM_FAILURE = 1,
+	LCS_CAUSE_PROTOCOL_ERROR = 2,
+	LCS_CAUSE_DATA_MISSING_IN_REQ = 3,
+	LCS_CAUSE_UNEXP_DATA_IN_REQ = 4,
+	LCS_CAUSE_POS_METH_FAILURE = 5,
+	LCS_CAUSE_TGT_MS_UNREACHABLE = 6,
+	LCS_CAUSE_REQUEST_ABORTED = 7,
+	LCS_CAUSE_FACILITY_NOTSUPP = 8,
+	LCS_CAUSE_INTER_BSC_HO = 9,
+	LCS_CAUSE_INTRA_BSC_HO = 10,
+	LCS_CAUSE_CONGESTION = 11,
+	LCS_CAUSE_INTER_NSE_CHG = 12,
+	LCS_CAUSE_RA_UPDAT = 13,
+	LCS_CAUSE_PTMSI_REALLOC = 14,
+	LCS_CAUSE_GPRS_SUSPENSION = 15,
+};
+
+/*! 3GPP TS 49.031 10.13 LCS Cause, also in 3GPP TS 48.008 3.2.2.66, which simply refers to the former. */
+struct lcs_cause_ie {
+	bool present;
+	enum lcs_cause cause_val;
+	bool diag_val_present;
+	uint8_t diag_val;
+};
+
+/*! @} */