Index: dialin/protocols/CAN.py
===================================================================
diff -u -r36d927b9a28017a71935fd76a3249466d9a576b5 -r8ab23ed705264e4cdc7e43689d01f9c243ed612b
--- dialin/protocols/CAN.py	(.../CAN.py)	(revision 36d927b9a28017a71935fd76a3249466d9a576b5)
+++ dialin/protocols/CAN.py	(.../CAN.py)	(revision 8ab23ed705264e4cdc7e43689d01f9c243ed612b)
@@ -464,7 +464,8 @@
         @return: DialityCanMessenger object
 
         """
-
+        self.message_queue_mutex = threading.Lock()
+        self.response_dictionary_mutex = threading.Lock()
         self.logger = logger
         self.log_can = log_can
         self.message_queue = deque()
@@ -647,6 +648,7 @@
 
                             # If it is not, this is a publication message and we need to call it's register function
                             else:
+                                self.message_queue_mutex.acquire()
                                 if DenaliCanMessenger.is_ui_received_channel(dialin_ch_id):  # check if the channel is in ui channels
                                     if self.ui_received_function_ptr is not None:
                                         self.thread_pool_executor.submit(
@@ -659,8 +661,8 @@
                                     for function_id in self.sync_response_dictionary[dialin_ch_id][dialin_msg_id]:
                                         self.thread_pool_executor.submit(
                                             self.sync_response_dictionary[dialin_ch_id][dialin_msg_id][function_id],
-                                            complete_dialin_message
-                                        )
+                                            complete_dialin_message)
+                                self.message_queue_mutex.release()
                         else:
                             self.logger.critical("Invalid message: {}\n".format(self.messages))
 
@@ -697,6 +699,7 @@
         # function_id is a UID for each callback per channel,msg pair.
         function_id = id(function)
         # if the channel_id exist, we update the dictionary for the channel_id
+        self.response_dictionary_mutex.acquire()
         if channel_id in self.sync_response_dictionary.keys():
             if message_id in self.sync_response_dictionary[channel_id].keys():
                 self.sync_response_dictionary[channel_id][message_id].update({function_id: function})
@@ -706,6 +709,7 @@
         # otherwise, we need to create the dictionary for the channel_id, msg_id pair
         else:
             self.sync_response_dictionary[channel_id] = {message_id: {function_id: function}}
+        self.response_dictionary_mutex.release()
 
     def register_received_all_ui_publication_function(self, function_ptr: Callable):
         """