diff --git a/CMakeLists.txt b/CMakeLists.txt
index e359e42e86bd445c28e26dd916814051800460c4..fbecb5ed9377df7c5a9f236a2a5ac7918baea81b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -2,7 +2,7 @@ project(cellframe-sdk C)
 cmake_minimum_required(VERSION 3.0)
 
 set(CMAKE_C_STANDARD 11)
-set(CELLFRAME_SDK_NATIVE_VERSION "2.9-27")
+set(CELLFRAME_SDK_NATIVE_VERSION "2.9-28")
 add_definitions ("-DCELLFRAME_SDK_VERSION=\"${CELLFRAME_SDK_NATIVE_VERSION}\"")
 set(DAPSDK_MODULES "")
 message("Cellframe modules: ${CELLFRAME_MODULES}")
diff --git a/modules/net/dap_chain_net.c b/modules/net/dap_chain_net.c
index 8e9ee6717d74f190ea7aff05065d50e2000a9832..6dfd45a8ef99b8afdffb8493c5dfb052c9c3ddaa 100644
--- a/modules/net/dap_chain_net.c
+++ b/modules/net/dap_chain_net.c
@@ -392,7 +392,9 @@ static void s_chain_callback_notify(void * a_arg, dap_chain_t *a_chain, dap_chai
         pthread_rwlock_rdlock(&PVT(l_net)->rwlock);
         for (dap_list_t *l_tmp = PVT(l_net)->links; l_tmp; l_tmp = dap_list_next(l_tmp)) {
             dap_chain_node_client_t *l_node_client = (dap_chain_node_client_t *)l_tmp->data;
-            dap_stream_ch_chain_pkt_write_mt( dap_client_get_stream_worker( l_node_client->client), l_node_client->ch_chain_uuid, DAP_STREAM_CH_CHAIN_PKT_TYPE_CHAIN,
+            dap_worker_t * l_worker = dap_client_get_stream_worker( l_node_client->client);
+            if(l_worker)
+                dap_stream_ch_chain_pkt_write_mt(l_worker, l_node_client->ch_chain_uuid, DAP_STREAM_CH_CHAIN_PKT_TYPE_CHAIN,
                                               l_net->pub.id.uint64, a_chain->id.uint64, a_id.uint64, a_atom, a_atom_size);
         }
         pthread_rwlock_unlock(&PVT(l_net)->rwlock);