diff --git a/openbsc/include/openbsc/gprs_sgsn.h b/openbsc/include/openbsc/gprs_sgsn.h
index e707c77..2ed46ff 100644
--- a/openbsc/include/openbsc/gprs_sgsn.h
+++ b/openbsc/include/openbsc/gprs_sgsn.h
@@ -304,6 +304,7 @@
 #define GPRS_SUBSCRIBER_UPDATE_AUTH_INFO_PENDING	(1 << 16)
 #define GPRS_SUBSCRIBER_UPDATE_LOCATION_PENDING		(1 << 17)
 #define GPRS_SUBSCRIBER_CANCELLED			(1 << 18)
+#define GPRS_SUBSCRIBER_ENABLE_PURGE			(1 << 19)
 
 #define GPRS_SUBSCRIBER_UPDATE_PENDING_MASK ( \
 		GPRS_SUBSCRIBER_UPDATE_LOCATION_PENDING | \
diff --git a/openbsc/src/gprs/gprs_subscriber.c b/openbsc/src/gprs/gprs_subscriber.c
index 9d79f00..58203ba 100644
--- a/openbsc/src/gprs/gprs_subscriber.c
+++ b/openbsc/src/gprs/gprs_subscriber.c
@@ -104,10 +104,27 @@
 	LOGGSUBSCRP(LOGL_INFO, subscr,
 		    "Expired, deleting subscriber entry\n");
 
+	subscr_get(subscr);
+
+	/* Check, whether to cleanup immediately */
+	if (!(subscr->flags & GPRS_SUBSCRIBER_ENABLE_PURGE))
+		goto force_cleanup;
+
+	/* Send a 'purge MS' message to the HLR */
+	if (gprs_subscr_purge(subscr) < 0)
+		goto force_cleanup;
+
+	/* Purge request has been sent */
+
+	subscr_put(subscr);
+	return;
+
+force_cleanup:
 	/* Make sure, the timer is cleaned up */
 	subscr->keep_in_ram = 0;
 	gprs_subscr_stop_timer(subscr);
 	/* The subscr is freed now, if the timer was the last user */
+	subscr_put(subscr);
 }
 
 static struct sgsn_subscriber_data *sgsn_subscriber_data_alloc(void *ctx)
@@ -169,6 +186,7 @@
 {
 	subscr->authorized = 0;
 	subscr->flags |= GPRS_SUBSCRIBER_CANCELLED;
+	subscr->flags &= ~GPRS_SUBSCRIBER_ENABLE_PURGE;
 
 	gprs_subscr_update(subscr);
 
@@ -258,6 +276,8 @@
 	subscr->authorized = 1;
 	subscr->sgsn_data->error_cause = 0;
 
+	subscr->flags |= GPRS_SUBSCRIBER_ENABLE_PURGE;
+
 	gprs_subscr_update(subscr);
 	return 0;
 }
@@ -377,6 +397,51 @@
 	return -gsup_msg->cause;
 }
 
+static int gprs_subscr_handle_gsup_purge_res(struct gsm_subscriber *subscr,
+					     struct gprs_gsup_message *gsup_msg)
+{
+	LOGGSUBSCRP(LOGL_INFO, subscr, "Completing purge MS\n");
+
+	/* Force silent cancellation */
+	subscr->sgsn_data->error_cause = 0;
+	gprs_subscr_put_and_cancel(subscr_get(subscr));
+
+	return 0;
+}
+
+static int gprs_subscr_handle_gsup_purge_err(struct gsm_subscriber *subscr,
+					     struct gprs_gsup_message *gsup_msg)
+{
+	LOGGSUBSCRP(LOGL_NOTICE, subscr,
+		    "Purge MS has failed with cause '%s' (%d)\n",
+		    get_value_string(gsm48_gmm_cause_names, gsup_msg->cause),
+		    gsup_msg->cause);
+
+	/* In GSM 09.02, 19.1.4.4, the text and the SDL diagram imply that
+	 * the subscriber data is not removed if the request has failed. On the
+	 * other hand, keeping the subscriber data in either error case
+	 * (subscriber unknown, syntactical message error, connection error)
+	 * doesn't seem to give any advantage, since the data will be restored
+	 * on the next Attach Request anyway.
+	 * This approach ensures, that the subscriber record will not stick if
+	 * an error happens.
+	 */
+
+	/* TODO: Check whether this behaviour is acceptable and either just
+	 * remove this TODO-notice or change the implementation to not delete
+	 * the subscriber data (eventually resetting the ENABLE_PURGE flag and
+	 * restarting the expiry timer based on the cause).
+	 *
+	 * Subscriber Unknown: cancel subscr
+	 * Temporary network problems: do nothing (handled by timer based retry)
+	 * Message problems (syntax, nyi, ...): cancel subscr (retry won't help)
+	 */
+
+	gprs_subscr_handle_gsup_purge_res(subscr, gsup_msg);
+
+	return -gsup_msg->cause;
+}
+
 int gprs_subscr_rx_gsup_message(struct msgb *msg)
 {
 	uint8_t *data = msgb_l2(msg);
@@ -435,7 +500,13 @@
 		break;
 
 	case GPRS_GSUP_MSGT_PURGE_MS_ERROR:
+		rc = gprs_subscr_handle_gsup_purge_err(subscr, &gsup_msg);
+		break;
+
 	case GPRS_GSUP_MSGT_PURGE_MS_RESULT:
+		rc = gprs_subscr_handle_gsup_purge_res(subscr, &gsup_msg);
+		break;
+
 	case GPRS_GSUP_MSGT_INSERT_DATA_REQUEST:
 	case GPRS_GSUP_MSGT_DELETE_DATA_REQUEST:
 		LOGGSUBSCRP(LOGL_ERROR, subscr,
@@ -458,6 +529,16 @@
 	return rc;
 }
 
+int gprs_subscr_purge(struct gsm_subscriber *subscr)
+{
+	struct gprs_gsup_message gsup_msg = {0};
+
+	LOGGSUBSCRP(LOGL_INFO, subscr, "purging MS subscriber\n");
+
+	gsup_msg.message_type = GPRS_GSUP_MSGT_PURGE_MS_REQUEST;
+	return gprs_subscr_tx_gsup_message(subscr, &gsup_msg);
+}
+
 int gprs_subscr_query_auth_info(struct gsm_subscriber *subscr)
 {
 	struct gprs_gsup_message gsup_msg = {0};
@@ -514,6 +595,7 @@
 	if (!subscr) {
 		subscr = gprs_subscr_get_or_create(mmctx->imsi);
 		subscr->flags |= GSM_SUBSCRIBER_FIRST_CONTACT;
+		subscr->flags &= ~GPRS_SUBSCRIBER_ENABLE_PURGE;
 	}
 
 	if (strcpy(subscr->equipment.imei, mmctx->imei) != 0) {
diff --git a/openbsc/src/gprs/sgsn_vty.c b/openbsc/src/gprs/sgsn_vty.c
index 1241c17..ef4c8d8 100644
--- a/openbsc/src/gprs/sgsn_vty.c
+++ b/openbsc/src/gprs/sgsn_vty.c
@@ -463,7 +463,7 @@
 	}
 
 	if (subscr->flags)
-		vty_out(vty, "    Flags: %s%s%s%s%s",
+		vty_out(vty, "    Flags: %s%s%s%s%s%s",
 			subscr->flags & GSM_SUBSCRIBER_FIRST_CONTACT ?
 			"FIRST_CONTACT " : "",
 			subscr->flags & GPRS_SUBSCRIBER_CANCELLED ?
@@ -472,6 +472,8 @@
 			"UPDATE_LOCATION_PENDING " : "",
 			subscr->flags & GPRS_SUBSCRIBER_UPDATE_AUTH_INFO_PENDING ?
 			"AUTH_INFO_PENDING " : "",
+			subscr->flags & GPRS_SUBSCRIBER_ENABLE_PURGE ?
+			"ENABLE_PURGE " : "",
 			VTY_NEWLINE);
 
 	vty_out(vty, "    Use count: %u%s", subscr->use_count, VTY_NEWLINE);
diff --git a/openbsc/tests/sgsn/sgsn_test.c b/openbsc/tests/sgsn/sgsn_test.c
index d612652..8181061 100644
--- a/openbsc/tests/sgsn/sgsn_test.c
+++ b/openbsc/tests/sgsn/sgsn_test.c
@@ -1109,12 +1109,16 @@
 
 int my_gprs_gsup_client_send(struct gprs_gsup_client *gsupc, struct msgb *msg)
 {
-	struct gprs_gsup_message to_peer;
-	struct gprs_gsup_message from_peer;
+	struct gprs_gsup_message to_peer = {0};
+	struct gprs_gsup_message from_peer = {0};
 	struct msgb *reply_msg;
+	int rc;
 
 	/* Simulate the GSUP peer */
-	gprs_gsup_decode(msgb_data(msg), msgb_length(msg), &to_peer);
+	rc = gprs_gsup_decode(msgb_data(msg), msgb_length(msg), &to_peer);
+	OSMO_ASSERT(rc >= 0);
+	OSMO_ASSERT(to_peer.imsi[0] != 0);
+	strncpy(from_peer.imsi, to_peer.imsi, sizeof(from_peer.imsi));
 
 	/* This invalidates the pointers in to_peer */
 	msgb_free(msg);
@@ -1129,13 +1133,13 @@
 		return my_subscr_request_auth_info_gsup_auth(NULL);
 
 	case GPRS_GSUP_MSGT_PURGE_MS_REQUEST:
-		/* TODO: send RES/ERR */
-		return 0;
+		from_peer.message_type = GPRS_GSUP_MSGT_PURGE_MS_RESULT;
+		break;
 
 	default:
 		if ((to_peer.message_type & 0b00000011) == 0) {
 			/* Unhandled request */
-			/* TODO: send error(NOT_IMPL) */
+			/* Send error(NOT_IMPL) */
 			from_peer.message_type = to_peer.message_type + 1;
 			from_peer.cause = GMM_CAUSE_MSGT_NOTEXIST_NOTIMPL;
 			break;