diff --git a/openbsc/include/openbsc/bsc_nat.h b/openbsc/include/openbsc/bsc_nat.h
index 15e2099..9d29d26 100644
--- a/openbsc/include/openbsc/bsc_nat.h
+++ b/openbsc/include/openbsc/bsc_nat.h
@@ -498,6 +498,10 @@
 int bsc_nat_extract_lac(struct bsc_connection *bsc, struct nat_sccp_connection *con,
 				struct bsc_nat_parsed *parsed, struct msgb *msg);
 
+/**
+ * CTRL interface helper
+ */
+void bsc_nat_inform_reject(struct bsc_connection *bsc, const char *imsi);
 
 /*
  * Use for testing
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat.c b/openbsc/src/osmo-bsc_nat/bsc_nat.c
index 6b061bc..2f6711a 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat.c
@@ -1060,6 +1060,8 @@
 			filter = bsc_nat_filter_sccp_cr(bsc, msg, parsed,
 						&con_type, &imsi, &cause);
 			if (filter < 0) {
+				if (imsi)
+					bsc_nat_inform_reject(bsc, imsi);
 				bsc_stat_reject(filter, bsc, 0);
 				goto exit3;
 			}
@@ -1091,6 +1093,8 @@
 					filter = bsc_nat_filter_dt(bsc, msg,
 							con, parsed, &cause);
 					if (filter < 0) {
+						if (imsi)
+							bsc_nat_inform_reject(bsc, imsi);
 						bsc_stat_reject(filter, bsc, 1);
 						bsc_send_con_release(bsc, con, &cause);
 						con = NULL;
diff --git a/openbsc/src/osmo-bsc_nat/bsc_nat_ctrl.c b/openbsc/src/osmo-bsc_nat/bsc_nat_ctrl.c
index 1a45e76..6aa2ff0 100644
--- a/openbsc/src/osmo-bsc_nat/bsc_nat_ctrl.c
+++ b/openbsc/src/osmo-bsc_nat/bsc_nat_ctrl.c
@@ -412,3 +412,21 @@
 	return NULL;
 }
 
+void bsc_nat_inform_reject(struct bsc_connection *conn, const char *imsi)
+{
+	struct ctrl_cmd *cmd;
+
+	cmd = ctrl_cmd_create(conn, CTRL_TYPE_TRAP);
+	if (!cmd) {
+		LOGP(DCTRL, LOGL_ERROR, "Failed to create TRAP command.\n");
+		return;
+	}
+
+	cmd->id = "0";
+	cmd->variable = talloc_asprintf(cmd, "net.0.bsc.%d.notification-rejection-v1",
+					conn->cfg->nr);
+	cmd->reply = talloc_asprintf(cmd, "imsi=%s", imsi);
+
+	ctrl_cmd_send_to_all(conn->cfg->nat->ctrl, cmd);
+	talloc_free(cmd);
+}