diff --git a/include/xeus-zmq/xclient_zmq.hpp b/include/xeus-zmq/xclient_zmq.hpp
index 2194938..1397c3b 100644
--- a/include/xeus-zmq/xclient_zmq.hpp
+++ b/include/xeus-zmq/xclient_zmq.hpp
@@ -29,6 +29,7 @@ namespace xeus
     public:
 
         using listener = std::function<void(xmessage)>;
+        using iopub_listener = std::function<void(xpub_message)>;
         using kernel_status_listener = std::function<void(bool)>;
 
         explicit xclient_zmq(std::unique_ptr<xclient_zmq_impl> impl);
@@ -42,16 +43,16 @@ namespace xeus
 
         void register_shell_listener(const listener& l);
         void register_control_listener(const listener& l);
-        void register_iopub_listener(const listener& l);
+        void register_iopub_listener(const iopub_listener& l);
         void register_kernel_status_listener(const kernel_status_listener& l);
 
         void notify_shell_listener(xmessage msg);
         void notify_control_listener(xmessage msg);
-        void notify_iopub_listener(xmessage msg);
+        void notify_iopub_listener(xpub_message msg);
         void notify_kernel_dead(bool status);
 
         std::size_t iopub_queue_size() const;
-        std::optional<xmessage> pop_iopub_message();
+        std::optional<xpub_message> pop_iopub_message();
         void connect();
         void stop_channels();
         void start();
diff --git a/src/client/xclient_zmq.cpp b/src/client/xclient_zmq.cpp
index 61fa71d..2279d65 100644
--- a/src/client/xclient_zmq.cpp
+++ b/src/client/xclient_zmq.cpp
@@ -53,7 +53,7 @@ namespace xeus
         p_client_impl->register_control_listener(l);
     }
 
-    void xclient_zmq::register_iopub_listener(const listener& l)
+    void xclient_zmq::register_iopub_listener(const iopub_listener& l)
     {
         p_client_impl->register_iopub_listener(l);
     }
@@ -73,7 +73,7 @@ namespace xeus
         p_client_impl->notify_control_listener(std::move(msg));
     }
 
-    void xclient_zmq::notify_iopub_listener(xmessage msg)
+    void xclient_zmq::notify_iopub_listener(xpub_message msg)
     {
         p_client_impl->notify_iopub_listener(std::move(msg));
     }
@@ -88,7 +88,7 @@ namespace xeus
         return p_client_impl->iopub_queue_size();
     }
 
-    std::optional<xmessage> xclient_zmq::pop_iopub_message()
+    std::optional<xpub_message> xclient_zmq::pop_iopub_message()
     {
         return p_client_impl->pop_iopub_message();
     }
diff --git a/src/client/xclient_zmq_impl.cpp b/src/client/xclient_zmq_impl.cpp
index 67a9cc9..23b08df 100644
--- a/src/client/xclient_zmq_impl.cpp
+++ b/src/client/xclient_zmq_impl.cpp
@@ -89,12 +89,12 @@ namespace xeus
         return m_iopub_client.iopub_queue_size();
     }
 
-    std::optional<xmessage> xclient_zmq_impl::pop_iopub_message()
+    std::optional<xpub_message> xclient_zmq_impl::pop_iopub_message()
     {
         return m_iopub_client.pop_iopub_message();
     }
 
-    void xclient_zmq_impl::register_iopub_listener(const listener& l)
+    void xclient_zmq_impl::register_iopub_listener(const iopub_listener& l)
     {
         m_iopub_listener = l;
     }
@@ -124,7 +124,7 @@ namespace xeus
         m_control_listener(std::move(msg));
     }
 
-    void xclient_zmq_impl::notify_iopub_listener(xmessage msg)
+    void xclient_zmq_impl::notify_iopub_listener(xpub_message msg)
     {
         m_iopub_listener(std::move(msg));
     }
@@ -169,7 +169,7 @@ namespace xeus
 
     void xclient_zmq_impl::wait_for_message()
     {
-        std::optional<xmessage> pending_message = pop_iopub_message();
+        std::optional<xpub_message> pending_message = pop_iopub_message();
 
         if (pending_message.has_value())
         {
@@ -200,4 +200,9 @@ namespace xeus
         return xzmq_serializer::deserialize(wire_msg, *p_auth);
     }
 
+    xpub_message xclient_zmq_impl::deserialize_iopub(zmq::multipart_t& wire_msg) const
+    {
+        return xzmq_serializer::deserialize_iopub(wire_msg, *p_auth);
+    }
+
 }
diff --git a/src/client/xclient_zmq_impl.hpp b/src/client/xclient_zmq_impl.hpp
index b52aa80..12477b6 100644
--- a/src/client/xclient_zmq_impl.hpp
+++ b/src/client/xclient_zmq_impl.hpp
@@ -34,6 +34,7 @@ namespace xeus
         using iopub_client_ptr = std::unique_ptr<xiopub_client>;
         using heartbeat_client_ptr = std::unique_ptr<xheartbeat_client>;
         using listener = std::function<void(xmessage)>;
+        using iopub_listener = std::function<void(xpub_message)>;
         using kernel_status_listener = std::function<void(bool)>;
 
         xclient_zmq_impl(zmq::context_t& context,
@@ -60,8 +61,8 @@ namespace xeus
 
         // iopub channel
         std::size_t iopub_queue_size() const;
-        std::optional<xmessage> pop_iopub_message();
-        void register_iopub_listener(const listener& l);
+        std::optional<xpub_message> pop_iopub_message();
+        void register_iopub_listener(const iopub_listener& l);
 
         // heartbeat channel
         void register_kernel_status_listener(const kernel_status_listener& l);
@@ -72,13 +73,14 @@ namespace xeus
 
         void notify_shell_listener(xmessage msg);
         void notify_control_listener(xmessage msg);
-        void notify_iopub_listener(xmessage msg);
+        void notify_iopub_listener(xpub_message msg);
         void notify_kernel_dead(bool status);
 
         void wait_for_message();
         void start();
 
         xmessage deserialize(zmq::multipart_t& wire_msg) const;
+        xpub_message deserialize_iopub(zmq::multipart_t& wire_msg) const;
 
     private:
         void start_iopub_thread();
@@ -99,7 +101,7 @@ namespace xeus
 
         listener m_shell_listener;
         listener m_control_listener;
-        listener m_iopub_listener;
+        iopub_listener m_iopub_listener;
 
         iopub_client_ptr p_iopub_client;
         heartbeat_client_ptr p_heartbeat_client;
diff --git a/src/client/xiopub_client.cpp b/src/client/xiopub_client.cpp
index 05a0d85..019fa2a 100644
--- a/src/client/xiopub_client.cpp
+++ b/src/client/xiopub_client.cpp
@@ -36,12 +36,12 @@ namespace xeus
         return m_message_queue.size();
     }
 
-    std::optional<xmessage> xiopub_client::pop_iopub_message()
+    std::optional<xpub_message> xiopub_client::pop_iopub_message()
     {
         std::lock_guard<std::mutex> guard(m_queue_mutex);
         if (!m_message_queue.empty())
         {
-            xmessage msg = std::move(m_message_queue.back());
+            xpub_message msg = std::move(m_message_queue.back());
             m_message_queue.pop();
             return msg;
         } else {
@@ -64,7 +64,7 @@ namespace xeus
                 if (items[0].revents & ZMQ_POLLIN)
                 {
                     wire_msg.recv(m_iopub);
-                    xmessage msg = p_client_impl->deserialize(wire_msg);
+                    xpub_message msg = p_client_impl->deserialize_iopub(wire_msg);
                     {
                         std::lock_guard<std::mutex> guard(m_queue_mutex);
                         m_message_queue.push(std::move(msg));
diff --git a/src/client/xiopub_client.hpp b/src/client/xiopub_client.hpp
index 79689fb..f1d149a 100644
--- a/src/client/xiopub_client.hpp
+++ b/src/client/xiopub_client.hpp
@@ -32,7 +32,7 @@ namespace xeus
         ~xiopub_client();
 
         std::size_t iopub_queue_size() const;
-        std::optional<xmessage> pop_iopub_message();
+        std::optional<xpub_message> pop_iopub_message();
 
         void run();
 
@@ -40,7 +40,7 @@ namespace xeus
         zmq::socket_t m_iopub;
         zmq::socket_t m_controller;
 
-        std::queue<xmessage> m_message_queue;
+        std::queue<xpub_message> m_message_queue;
         mutable std::mutex m_queue_mutex;
 
         xclient_zmq_impl* p_client_impl;