diff --git a/src/Makefile.am b/src/Makefile.am
index 60fc479..ea5023d 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -52,6 +52,7 @@
 	rand_urandom.c \
 	hlr_vty.c \
 	hlr_vty_subscr.c \
+	gsup_send.c \
 	$(NULL)
 
 osmo_hlr_LDADD = \
diff --git a/src/gsup_send.c b/src/gsup_send.c
new file mode 100644
index 0000000..b2c4e02
--- /dev/null
+++ b/src/gsup_send.c
@@ -0,0 +1,45 @@
+/* (C) 2018 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/>.
+ *
+ */
+
+/* This is kept separate to be able to override the actual sending functions from unit tests. */
+
+#include <errno.h>
+
+#include "gsup_server.h"
+#include "gsup_router.h"
+
+#include <osmocom/core/logging.h>
+
+/* Send a msgb to a given address using routing */
+int osmo_gsup_addr_send(struct osmo_gsup_server *gs,
+			const uint8_t *addr, size_t addrlen,
+			struct msgb *msg)
+{
+	struct osmo_gsup_conn *conn;
+
+	conn = gsup_route_find(gs, addr, addrlen);
+	if (!conn) {
+		DEBUGP(DLGSUP, "Cannot find route for addr %s\n", addr);
+		msgb_free(msg);
+		return -ENODEV;
+	}
+
+	return osmo_gsup_conn_send(conn, msg);
+}
+
diff --git a/src/luop.c b/src/luop.c
index 54c3884..edf4c51 100644
--- a/src/luop.c
+++ b/src/luop.c
@@ -165,23 +165,6 @@
 	luop->state = new_state;
 }
 
-/* Send a msgb to a given address using routing */
-int osmo_gsup_addr_send(struct osmo_gsup_server *gs,
-			const uint8_t *addr, size_t addrlen,
-			struct msgb *msg)
-{
-	struct osmo_gsup_conn *conn;
-
-	conn = gsup_route_find(gs, addr, addrlen);
-	if (!conn) {
-		DEBUGP(DMAIN, "Cannot find route for addr %s\n", addr);
-		msgb_free(msg);
-		return -ENODEV;
-	}
-
-	return osmo_gsup_conn_send(conn, msg);
-}
-
 /*! Transmit UPD_LOC_ERROR and destroy lu_operation */
 void lu_op_tx_error(struct lu_operation *luop, enum gsm48_gmm_cause cause)
 {
diff --git a/src/luop.h b/src/luop.h
index 053a025..d690243 100644
--- a/src/luop.h
+++ b/src/luop.h
@@ -28,6 +28,7 @@
 #include <osmocom/gsm/gsup.h>
 
 #include "db.h"
+#include "gsup_server.h"
 
 #define CANCEL_TIMEOUT_SECS	30
 #define ISD_TIMEOUT_SECS	30