--- a/pjsip/src/pjsua-lib/pjsua_acc.c
+++ b/pjsip/src/pjsua-lib/pjsua_acc.c
@@ -430,7 +430,7 @@
 		     "<sip:%s%.*s%s:%d%s>", 
 		     beginquote,
 		     (int)t->local_name.host.slen,
-		     t->local_name.host.ptr,
+		     t->local_name.host.slen ? t->local_name.host.ptr : "",
 		     endquote,
 		     t->local_name.port,
 		     transport_param);
@@ -1158,18 +1158,18 @@
 	len = pj_ansi_snprintf(tmp, PJSIP_MAX_URL_SIZE,
 			       "<sip:%.*s%s%s%.*s%s:%d;transport=%s%.*s>%.*s",
 			       (int)acc->user_part.slen,
-			       acc->user_part.ptr,
+			       acc->user_part.slen ? acc->user_part.ptr : "",
 			       (acc->user_part.slen? "@" : ""),
 			       beginquote,
 			       (int)via_addr->slen,
-			       via_addr->ptr,
+			       via_addr->slen ? via_addr->ptr : "",
 			       endquote,
 			       rport,
 			       tp->type_name,
 			       (int)acc->cfg.contact_uri_params.slen,
-			       acc->cfg.contact_uri_params.ptr,
+			       acc->cfg.contact_uri_params.slen ? acc->cfg.contact_uri_params.ptr : "",
 			       (int)acc->cfg.contact_params.slen,
-			       acc->cfg.contact_params.ptr);
+			       acc->cfg.contact_params.slen ? acc->cfg.contact_params.ptr : "");
 	if (len < 1) {
 	    PJ_LOG(1,(THIS_FILE, "URI too long"));
 	    pj_pool_release(pool);
@@ -2233,22 +2233,22 @@
     contact->slen = pj_ansi_snprintf(contact->ptr, PJSIP_MAX_URL_SIZE,
 				     "%.*s%s<%s:%.*s%s%s%.*s%s:%d%s%.*s>%.*s",
 				     (int)acc->display.slen,
-				     acc->display.ptr,
+				     acc->display.slen ? acc->display.ptr : "",
 				     (acc->display.slen?" " : ""),
 				     (secure ? PJSUA_SECURE_SCHEME : "sip"),
 				     (int)acc->user_part.slen,
-				     acc->user_part.ptr,
+				     acc->user_part.slen ? acc->user_part.ptr : "",
 				     (acc->user_part.slen?"@":""),
 				     beginquote,
 				     (int)local_addr.slen,
-				     local_addr.ptr,
+				     local_addr.slen ? local_addr.ptr : "",
 				     endquote,
 				     local_port,
 				     transport_param,
 				     (int)acc->cfg.contact_uri_params.slen,
-				     acc->cfg.contact_uri_params.ptr,
+				     acc->cfg.contact_uri_params.slen ? acc->cfg.contact_uri_params.ptr : "",
 				     (int)acc->cfg.contact_params.slen,
-				     acc->cfg.contact_params.ptr);
+				     acc->cfg.contact_params.slen ? acc->cfg.contact_params.ptr : "");
 
     return PJ_SUCCESS;
 }
@@ -2390,22 +2390,22 @@
     contact->slen = pj_ansi_snprintf(contact->ptr, PJSIP_MAX_URL_SIZE,
 				     "%.*s%s<%s:%.*s%s%s%.*s%s:%d%s%.*s>%.*s",
 				     (int)acc->display.slen,
-				     acc->display.ptr,
+				     acc->display.slen ? acc->display.ptr : "",
 				     (acc->display.slen?" " : ""),
 				     (secure ? PJSUA_SECURE_SCHEME : "sip"),
 				     (int)acc->user_part.slen,
-				     acc->user_part.ptr,
+				     acc->user_part.slen ? acc->user_part.ptr : "",
 				     (acc->user_part.slen?"@":""),
 				     beginquote,
 				     (int)local_addr.slen,
-				     local_addr.ptr,
+				     local_addr.slen ? local_addr.ptr : "",
 				     endquote,
 				     local_port,
 				     transport_param,
 				     (int)acc->cfg.contact_uri_params.slen,
-				     acc->cfg.contact_uri_params.ptr,
+				     acc->cfg.contact_uri_params.slen ? acc->cfg.contact_uri_params.ptr : "",
 				     (int)acc->cfg.contact_params.slen,
-				     acc->cfg.contact_params.ptr);
+				     acc->cfg.contact_params.slen ? acc->cfg.contact_params.ptr : "");
 
     return PJ_SUCCESS;
 }