diff --git a/include/osmocom/hlr/dgsm.h b/include/osmocom/hlr/dgsm.h
new file mode 100644
index 0000000..f06e381
--- /dev/null
+++ b/include/osmocom/hlr/dgsm.h
@@ -0,0 +1,45 @@
+/* Copyright 2019 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * All Rights Reserved
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation; either version 3 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 Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#pragma once
+
+#include <osmocom/mslookup/mslookup.h>
+#include <osmocom/hlr/gsup_server.h>
+#include <osmocom/gsupclient/gsup_peer_id.h>
+#include <osmocom/gsupclient/gsup_req.h>
+
+#define LOG_DGSM(imsi, level, fmt, args...) \
+	LOGP(DDGSM, level, "(IMSI-%s) " fmt, imsi, ##args)
+
+struct vty;
+struct remote_hlr;
+struct hlr_subscriber;
+
+extern void *dgsm_ctx;
+
+void dgsm_init(void *ctx);
+void dgsm_start(void *ctx);
+void dgsm_stop();
+
+bool dgsm_check_forward_gsup_msg(struct osmo_gsup_req *req);
+
+void dgsm_vty_init();
+void dgsm_mdns_client_config_apply(void);
+
+bool hlr_subscr_lu_age(const struct hlr_subscriber *subscr, uint32_t *age_p);