diff --git a/src/client/xclient_zmq_impl.cpp b/src/client/xclient_zmq_impl.cpp
index 23b08df..f4be177 100644
--- a/src/client/xclient_zmq_impl.cpp
+++ b/src/client/xclient_zmq_impl.cpp
@@ -27,7 +27,7 @@ namespace xeus
         : p_auth(make_xauthentication(config.m_signature_scheme, config.m_key))
         , m_shell_client(context, config.m_transport, config.m_ip, config.m_shell_port)
         , m_control_client(context, config.m_transport, config.m_ip, config.m_control_port)
-        , m_iopub_client(context, config)
+        , m_iopub_client(context, config, this)
         , m_heartbeat_client(context, config, max_retry, heartbeat_timeout)
         , p_messenger(context)
         , m_error_handler(eh)
@@ -174,7 +174,9 @@ namespace xeus
         if (pending_message.has_value())
         {
             notify_iopub_listener(std::move(*pending_message));
-        } else {
+        }
+        else
+        {
             poll(-1);
         }
     }
@@ -187,12 +189,12 @@ namespace xeus
 
     void xclient_zmq_impl::start_iopub_thread()
     {
-        m_iopub_thread = std::move(xthread(&xiopub_client::run, p_iopub_client.get()));
+        m_iopub_thread = std::move(xthread(&xiopub_client::run, &m_iopub_client));
     }
 
     void xclient_zmq_impl::start_heartbeat_thread()
     {
-        m_heartbeat_thread = std::move(xthread(&xheartbeat_client::run, p_heartbeat_client.get()));
+        m_heartbeat_thread = std::move(xthread(&xheartbeat_client::run, &m_heartbeat_client));
     }
 
     xmessage xclient_zmq_impl::deserialize(zmq::multipart_t& wire_msg) const
diff --git a/src/client/xclient_zmq_impl.hpp b/src/client/xclient_zmq_impl.hpp
index 12477b6..f733865 100644
--- a/src/client/xclient_zmq_impl.hpp
+++ b/src/client/xclient_zmq_impl.hpp
@@ -103,9 +103,6 @@ namespace xeus
         listener m_control_listener;
         iopub_listener m_iopub_listener;
 
-        iopub_client_ptr p_iopub_client;
-        heartbeat_client_ptr p_heartbeat_client;
-
         xthread m_iopub_thread;
         xthread m_heartbeat_thread;
     };
diff --git a/src/client/xheartbeat_client.cpp b/src/client/xheartbeat_client.cpp
index 5046ff4..f84e3e9 100644
--- a/src/client/xheartbeat_client.cpp
+++ b/src/client/xheartbeat_client.cpp
@@ -70,11 +70,15 @@ namespace xeus
                 if (retry_count < m_max_retry)
                 {
                     ++retry_count;
-                } else {
+                }
+                else
+                {
                     notify_kernel_dead(true);
                     stop = true;
                 }
-            } else {
+            }
+            else
+            {
                 retry_count = 0;
             }
             std::this_thread::sleep_for(std::chrono::milliseconds(100));
diff --git a/src/client/xiopub_client.cpp b/src/client/xiopub_client.cpp
index 6213103..00158ef 100644
--- a/src/client/xiopub_client.cpp
+++ b/src/client/xiopub_client.cpp
@@ -18,13 +18,16 @@ namespace xeus
 {
 
     xiopub_client::xiopub_client(zmq::context_t& context,
-                                 const xeus::xconfiguration& config)
+                                 const xeus::xconfiguration& config,
+                                 xclient_zmq_impl* client)
         : m_iopub(context, zmq::socket_type::sub)
         , m_controller(context, zmq::socket_type::rep)
         , m_iopub_end_point("")
+        , p_client_impl(client)
     {
         m_iopub_end_point = get_end_point(config.m_transport, config.m_ip, config.m_iopub_port);
         m_iopub.connect(m_iopub_end_point);
+        m_iopub.set(zmq::sockopt::subscribe, "");
         init_socket(m_controller, get_controller_end_point("iopub"));
     }
 
@@ -47,7 +50,9 @@ namespace xeus
             xpub_message msg = std::move(m_message_queue.back());
             m_message_queue.pop();
             return msg;
-        } else {
+        }
+        else
+        {
             return std::nullopt;
         }
     }
diff --git a/src/client/xiopub_client.hpp b/src/client/xiopub_client.hpp
index 2acb731..6b04b06 100644
--- a/src/client/xiopub_client.hpp
+++ b/src/client/xiopub_client.hpp
@@ -27,7 +27,8 @@ namespace xeus
     public:
 
         xiopub_client(zmq::context_t& context,
-                        const xeus::xconfiguration& config);
+                      const xeus::xconfiguration& config,
+                      xclient_zmq_impl* client);
 
         ~xiopub_client();
 
@@ -49,4 +50,4 @@ namespace xeus
     };
 }
 
-#endif
\ No newline at end of file
+#endif