diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index 6fc4f99..197be9d 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -440,6 +440,12 @@
 		0x06, 0x01, 0x00,
 	};
 
+	static const uint8_t location_cancellation_req_withdraw[] = {
+		0x1c,
+		TEST_GSUP_IMSI1_IE,
+		0x06, 0x01, 0x01,
+	};
+
 	static const uint8_t location_cancellation_req_other[] = {
 		0x1c,
 		0x01, 0x05, 0x11, 0x11, 0x11, 0x11, 0x01,
@@ -582,6 +588,12 @@
 	OSMO_ASSERT(s1->flags & GPRS_SUBSCRIBER_CANCELLED);
 	OSMO_ASSERT(s1->sgsn_data->mm == NULL);
 
+	/* Inject LocCancelReq(withdraw) GSUP message */
+	rc = rx_gsup_message(location_cancellation_req_withdraw,
+			     sizeof(location_cancellation_req_withdraw));
+	OSMO_ASSERT(rc >= 0);
+	OSMO_ASSERT(s1->sgsn_data->error_cause == GMM_CAUSE_IMPL_DETACHED);
+
 	/* Inject PurgeMsRes GSUP message */
 	rc = rx_gsup_message(purge_ms_res,
 			     sizeof(purge_ms_res));