diff --git a/pjsip-apps/src/test-pjsua/scripts-sendto/500_pres_subscribe_with_bad_event.py b/pjsip-apps/src/test-pjsua/scripts-sendto/500_pres_subscribe_with_bad_event.py
new file mode 100644
index 0000000..70f5ab9
--- /dev/null
+++ b/pjsip-apps/src/test-pjsua/scripts-sendto/500_pres_subscribe_with_bad_event.py
@@ -0,0 +1,28 @@
+# $Id$
+import inc_sip as sip
+import inc_sdp as sdp
+
+# Ticket http://trac.pjsip.org/repos/ticket/623, based on
+# http://lists.pjsip.org/pipermail/pjsip_lists.pjsip.org/2008-September/004709.html:
+#
+# Assertion when receiving SUBSCRIBE with non-presence Event.
+complete_msg = \
+"""SUBSCRIBE sip:localhost;transport=UDP SIP/2.0
+Call-ID: f20e8783e764cae325dba17be4b8fe19@10.0.2.15
+CSeq: 1 SUBSCRIBE
+From: <sip:localhost>;tag=1710895
+To: <sip:localhost>
+Via: SIP/2.0/UDP localhost;rport;branch=z9hG4bKd88a.18c427d2.0
+Max-Forwards: 69
+Event:  message-summary
+Contact: <sip:localhost>
+Allow: NOTIFY, SUBSCRIBE
+Content-Length: 0
+
+"""
+
+
+sendto_cfg = sip.SendtoCfg( "Incoming SUBSCRIBE with non presence", 
+			    "--null-audio", 
+			    "", 489, complete_msg=complete_msg)
+
diff --git a/pjsip/src/pjsua-lib/pjsua_pres.c b/pjsip/src/pjsua-lib/pjsua_pres.c
index f0a2100..0e3cc21 100644
--- a/pjsip/src/pjsua-lib/pjsua_pres.c
+++ b/pjsip/src/pjsua-lib/pjsua_pres.c
@@ -718,9 +718,22 @@
     /* Create server presence subscription: */
     status = pjsip_pres_create_uas( dlg, &pres_cb, rdata, &sub);
     if (status != PJ_SUCCESS) {
-	pjsip_dlg_terminate(dlg);
+	int code = PJSIP_ERRNO_TO_SIP_STATUS(status);
+	pjsip_tx_data *tdata;
+
 	pjsua_perror(THIS_FILE, "Unable to create server subscription", 
 		     status);
+
+	if (code==599 || code > 699 || code < 300) {
+	    code = 400;
+	}
+
+	status = pjsip_dlg_create_response(dlg, rdata, code, NULL, &tdata);
+	if (status == PJ_SUCCESS) {
+	    status = pjsip_dlg_send_response(dlg, pjsip_rdata_get_tsx(rdata),
+					     tdata);
+	}
+
 	PJSUA_UNLOCK();
 	return PJ_TRUE;
     }