diff --git a/src/connector.c b/src/connector.c
index 17683f8b..b7973d5a 100644
--- a/src/connector.c
+++ b/src/connector.c
@@ -137,7 +137,7 @@ struct connector_data {
 	int clients_generated;
 	int dead_generated;
 
-	int64_t client_id;
+	int64_t client_ids;
 
 	/* client message process queue */
 	ckmsgq_t *cmpq;
@@ -243,6 +243,20 @@ static void recycle_client(cdata_t *cdata, client_instance_t *client)
 	ck_wunlock(&cdata->lock);
 }
 
+/* Allows the stratifier to get a unique local virtualid for subclients */
+int64_t connector_newclientid(ckpool_t *ckp)
+{
+	int64_t ret;
+
+	cdata_t *cdata = ckp->cdata;
+
+	ck_wlock(&cdata->lock);
+	ret = cdata->client_ids++;
+	ck_wunlock(&cdata->lock);
+
+	return ret;
+}
+
 /* Accepts incoming connections on the server socket and generates client
  * instances */
 static int accept_client(cdata_t *cdata, const int epfd, const uint64_t server)
@@ -310,7 +324,7 @@ static int accept_client(cdata_t *cdata, const int epfd, const uint64_t server)
 		cdata->nfds, fd, no_clients, client->address_name, port);
 
 	ck_wlock(&cdata->lock);
-	client->id = cdata->client_id++;
+	client->id = cdata->client_ids++;
 	HASH_ADD_I64(cdata->clients, id, client);
 	cdata->nfds++;
 	ck_wunlock(&cdata->lock);
@@ -1654,7 +1668,7 @@ void *connector(void *arg)
 	cdata->nfds = 0;
 	/* Set the client id to the highest serverurl count to distinguish
 	 * them from the server fds in epoll. */
-	cdata->client_id = ckp->serverurls;
+	cdata->client_ids = ckp->serverurls;
 	mutex_init(&cdata->sender_lock);
 	cond_init(&cdata->sender_cond);
 	create_pthread(&cdata->pth_sender, sender, cdata);
diff --git a/src/connector.h b/src/connector.h
index 4bb79bd0..be945ef3 100644
--- a/src/connector.h
+++ b/src/connector.h
@@ -10,6 +10,7 @@
 #ifndef CONNECTOR_H
 #define CONNECTOR_H
 
+int64_t connector_newclientid(ckpool_t *ckp);
 void connector_upstream_msg(ckpool_t *ckp, char *msg);
 void connector_add_message(ckpool_t *ckp, json_t *val);
 char *connector_stats(void *data, const int runtime);
diff --git a/src/stratifier.c b/src/stratifier.c
index 36a7bcac..93669bef 100644
--- a/src/stratifier.c
+++ b/src/stratifier.c
@@ -253,6 +253,9 @@ struct stratum_instance {
 	UT_hash_handle hh;
 	int64_t id;
 
+	/* Virtualid used as unique local id for passthrough clients */
+	int64_t virtualid;
+
 	stratum_instance_t *next;
 	stratum_instance_t *prev;
 
@@ -3357,7 +3360,7 @@ static stratum_instance_t *__recruit_stratum_instance(sdata_t *sdata)
 	return client;
 }
 
-/* Enter with write instance_lock held */
+/* Enter with write instance_lock held, drops and grabs it again */
 static stratum_instance_t *__stratum_add_instance(ckpool_t *ckp, int64_t id, const char *address,
 						  int server)
 {
@@ -3366,6 +3369,8 @@ static stratum_instance_t *__stratum_add_instance(ckpool_t *ckp, int64_t id, con
 	int64_t pass_id;
 
 	client = __recruit_stratum_instance(sdata);
+	ck_wunlock(&sdata->instance_lock);
+
 	client->start_time = time(NULL);
 	client->id = id;
 	client->session_id = ++sdata->session_id;
@@ -3377,7 +3382,6 @@ static stratum_instance_t *__stratum_add_instance(ckpool_t *ckp, int64_t id, con
 	client->diff = client->old_diff = ckp->startdiff;
 	client->ckp = ckp;
 	tv_time(&client->ldc);
-	HASH_ADD_I64(sdata->stratum_instances, id, client);
 	/* Points to ckp sdata in ckpool mode, but is changed later in proxy
 	 * mode . */
 	client->sdata = sdata;
@@ -3398,8 +3402,14 @@ static stratum_instance_t *__stratum_add_instance(ckpool_t *ckp, int64_t id, con
 			sprintf(client->identity, "passthrough:%"PRId64" subclient:%"PRId64,
 				pass_id, id);
 		}
-	} else
+		client->virtualid = connector_newclientid(ckp);
+	} else {
 		sprintf(client->identity, "%"PRId64, id);
+		client->virtualid = id;
+	}
+
+	ck_wlock(&sdata->instance_lock);
+	HASH_ADD_I64(sdata->stratum_instances, id, client);
 	return client;
 }
 
@@ -4453,8 +4463,6 @@ static void get_uptime(sdata_t *sdata, int *sockd)
 	send_api_response(val, *sockd);
 }
 
-static void srecv_process(ckpool_t *ckp, json_t *val);
-
 /* For emergency use only, flushes all pending ckdbq messages */
 static void ckdbq_flush(sdata_t *sdata)
 {
@@ -5862,23 +5870,28 @@ test_blocksolve(const stratum_instance_t *client, const workbase_t *wb, const uc
 	send_node_block(sdata, client->enonce1, nonce, nonce2, ntime32, wb->id,
 			diff, client->id);
 
-	JSON_CPACK(val, "{si,ss,ss,sI,ss,ss,sI,ss,ss,ss,sI,sf,ss,ss,ss,ss}",
-			"height", wb->height,
-			"blockhash", blockhash,
-			"confirmed", "n",
-			"workinfoid", wb->id,
-			"username", client->user_instance->username,
-			"workername", client->workername,
-			"clientid", client->id,
-			"enonce1", client->enonce1,
-			"nonce2", nonce2,
-			"nonce", nonce,
-			"reward", wb->coinbasevalue,
-		        "diff", diff,
-			"createdate", cdfield,
-			"createby", "code",
-			"createcode", __func__,
-			"createinet", ckp->serverurl[client->server]);
+	val = json_object();
+	// JSON_CPACK(val, "{si,ss,ss,sI,ss,ss,sI,ss,ss,ss,sI,sf,ss,ss,ss,ss}",
+	json_set_int(val, "height", wb->height);
+	json_set_string(val,"blockhash", blockhash);
+	json_set_string(val,"confirmed", "n");
+	json_set_int64(val, "workinfoid", wb->id);
+	json_set_string(val, "username", client->user_instance->username);
+	json_set_string(val, "workername", client->workername);
+	if (ckp->remote)
+		json_set_int64(val, "clientid", client->virtualid);
+	else
+		json_set_int64(val, "clientid", client->id);
+	json_set_string(val, "enonce1", client->enonce1);
+	json_set_string(val, "nonce2", nonce2);
+	json_set_string(val, "nonce", nonce);
+	json_set_int64(val, "reward", wb->coinbasevalue);
+	json_set_double(val, "diff", diff);
+	json_set_string(val, "createdate", cdfield);
+	json_set_string(val, "createby", "code");
+	json_set_string(val, "createcode", __func__);
+	json_set_string(val, "createinet", ckp->serverurl[client->server]);
+
 	val_copy = json_deep_copy(val);
 
 	if (ckp->remote) {
@@ -6180,7 +6193,10 @@ out_nowb:
 	/* Now write to the pool's sharelog. */
 	val = json_object();
 	json_set_int(val, "workinfoid", id);
-	json_set_int(val, "clientid", client->id);
+	if (ckp->remote)
+		json_set_int64(val, "clientid", client->virtualid);
+	else
+		json_set_int64(val, "clientid", client->id);
 	json_set_string(val, "enonce1", client->enonce1);
 	if (!CKP_STANDALONE(ckp))
 		json_set_string(val, "secondaryuserid", user->secondaryuserid);
@@ -6250,7 +6266,10 @@ out:
 	if (!share) {
 		if (!CKP_STANDALONE(ckp) || ckp->remote) {
 			val = json_object();
-			json_set_int(val, "clientid", client->id);
+			if (ckp->remote)
+				json_set_int64(val, "clientid", client->virtualid);
+			else
+				json_set_int64(val, "clientid", client->id);
 			if (user->secondaryuserid)
 				json_set_string(val, "secondaryuserid", user->secondaryuserid);
 			json_set_string(val, "enonce1", client->enonce1);
@@ -6564,13 +6583,13 @@ static void parse_method(ckpool_t *ckp, sdata_t *sdata, stratum_instance_t *clie
 	if (unlikely(cmdmatch(method, "mining.passthrough"))) {
 		char buf[256];
 
-		if (ckp->proxy || ckp->node || ckp->remote) {
+		if (ckp->proxy || ckp->node ) {
 			LOGNOTICE("Dropping client %s %s trying to connect as passthrough on unsupported server %d",
 				  client->identity, client->address, client->server);
 			connector_drop_client(ckp, client_id);
 			drop_client(ckp, sdata, client_id);
 		} else {
-			/* We need  is a passthrough and to manage its messages
+			/*Flag this as a passthrough and manage its messages
 			 * accordingly. No data from this client id should ever
 			 * come directly back to this stratifier. */
 			LOGNOTICE("Adding passthrough client %s %s", client->identity, client->address);
@@ -6861,6 +6880,31 @@ static void send_auth_failure(sdata_t *sdata, stratum_instance_t *client)
 	stratum_send_message(sdata, client, "Failed authorisation :(");
 }
 
+/* For finding a client by its virtualid instead of client->id. This is an
+ * inefficient lookup but only occurs once on parsing a remote auth from the
+ * upstream pool on passthrough subclients. */
+static stratum_instance_t *ref_instance_by_virtualid(sdata_t *sdata, int64_t *client_id)
+{
+	stratum_instance_t *client, *ret = NULL;
+
+	ck_wlock(&sdata->instance_lock);
+	for (client = sdata->stratum_instances; client; client = client->hh.next) {
+		if (likely(client->virtualid != *client_id))
+			continue;
+		if (likely(!client->dropped)) {
+			ret = client;
+			__inc_instance_ref(ret);
+			/* Replace the client_id with the correct one, allowing
+			 * us to send the response to the correct client */
+			*client_id = client->id;
+		}
+		break;
+	}
+	ck_wunlock(&sdata->instance_lock);
+
+	return ret;
+}
+
 void parse_upstream_auth(ckpool_t *ckp, json_t *val)
 {
 	json_t *id_val = NULL, *err_val = NULL;
@@ -6878,6 +6922,9 @@ void parse_upstream_auth(ckpool_t *ckp, json_t *val)
 		goto out;
 	err_val = json_object_get(val, "error");
 	client = ref_instance_by_id(sdata, client_id);
+	/* Is this client_id a virtualid from a passthrough subclient */
+	if (!client)
+		client = ref_instance_by_virtualid(sdata, &client_id);
 	if (!client) {
 		LOGINFO("Failed to find client id %"PRId64" in parse_upstream_auth",
 		        client_id);
@@ -7545,7 +7592,7 @@ static void upstream_auth(ckpool_t *ckp, stratum_instance_t *client, json_params
 	json_set_string(val, "useragent", client->useragent ? : "");
 	json_set_string(val, "enonce1", client->enonce1 ? : "");
 	json_set_string(val, "address", client->address);
-	json_set_int(val, "clientid", client->id);
+	json_set_int64(val, "clientid", client->virtualid);
 	msg = json_dumps(val, JSON_NO_UTF8 | JSON_PRESERVE_ORDER | JSON_COMPACT | JSON_EOL);
 	json_decref(val);
 	connector_upstream_msg(ckp, msg);