diff --git a/include/openbsc/iu_dummy.h b/include/openbsc/iu_dummy.h
new file mode 100644
index 0000000..d5e1428
--- /dev/null
+++ b/include/openbsc/iu_dummy.h
@@ -0,0 +1,51 @@
+/* Trivial switch-off of external Iu dependencies,
+ * allowing to run full unit tests even when built without Iu support. */
+
+/*
+ * (C) 2016,2017 by sysmocom s.f.m.c. GmbH <info@sysmocom.de>
+ *
+ * Author: Neels Hofmeyr <nhofmeyr@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/>.
+ *
+ */
+
+#include <stdint.h>
+#include <stdbool.h>
+
+#include <osmocom/core/linuxlist.h>
+
+struct msgb;
+struct gsm_auth_tuple;
+struct RANAP_Cause;
+struct osmo_auth_vector;
+
+struct ranap_ue_conn_ctx {
+	struct llist_head list;
+	uint32_t conn_id;
+};
+
+int ranap_iu_tx(struct msgb *msg, uint8_t sapi);
+int ranap_iu_tx_sec_mode_cmd(struct ranap_ue_conn_ctx *uectx, struct osmo_auth_vector *vec,
+			     int send_ck);
+int ranap_iu_page_cs(const char *imsi, const uint32_t *tmsi, uint16_t lac);
+int ranap_iu_page_ps(const char *imsi, const uint32_t *ptmsi, uint16_t lac, uint8_t rac);
+struct msgb *ranap_new_msg_rab_assign_voice(uint8_t rab_id, uint32_t rtp_ip,
+					    uint16_t rtp_port,
+					    bool use_x213_nsap);
+int ranap_iu_rab_act(struct ranap_ue_conn_ctx *ue_ctx, struct msgb *msg);
+int ranap_iu_tx_common_id(struct ranap_ue_conn_ctx *uectx, const char *imsi);
+int ranap_iu_tx_release(struct ranap_ue_conn_ctx *ctx, const struct RANAP_Cause *cause);