diff --git a/c/mqtt.c b/c/mqtt.c
index efecf05..9f49d68 100644
--- a/c/mqtt.c
+++ b/c/mqtt.c
@@ -38,6 +38,7 @@ static PL_engine_t current_engine;
 
 static atom_t ATOM_is_async;
 static atom_t ATOM_client_id;
+static atom_t ATOM_alias;
 static atom_t ATOM_keepalive;
 //static atom_t ATOM_use_callbacks;
 
@@ -215,6 +216,22 @@ destroy_mqtt(swi_mqtt *m)
   return TRUE;
 }
 
+static PL_thread_attr_t* get_callback_thread_attrs(char* th_alias)
+{
+  return NULL;
+  /*
+      PL_thread_attr_t *th_attrs = malloc(sizeof(PL_thread_attr_t));// customized prolog stack properties. Default is bit large at 100M each thread.
+      if (th_attrs==0) { return NULL; }
+      th_attrs->local_size=100;// K;
+      th_attrs->global_size=200;// K;
+      th_attrs->trail_size=200;// K;
+      th_attrs->argument_size=20;// K;
+      th_attrs->alias=th_alias; // "callback_thread";
+      th_attrs->cancel=0;
+  return th_attrs;
+  */
+}
+
 
 static int set_engine_for_callbacks(swi_mqtt *m)
 {
@@ -232,7 +249,8 @@ static int set_engine_for_callbacks(swi_mqtt *m)
   } else {
     if (!current_engine)
     {
-      current_engine = PL_create_engine(NULL);
+      
+      current_engine = PL_create_engine(get_callback_thread_attrs("th_callback_tmp"));
     }
     engine_to_use = current_engine;
   }
@@ -805,6 +823,7 @@ c_mqtt_connect(term_t conn, term_t host, term_t port, term_t options)
   int mqtt_port = 1883;
 
   char* client_id;
+  char* alias;
   int keepalive = 60;
   int is_async = FALSE;
   int use_hooks = FALSE;
@@ -857,6 +876,7 @@ c_mqtt_connect(term_t conn, term_t host, term_t port, term_t options)
             _PL_get_arg(1, head, arg);
 	  
   	        if        ( name == ATOM_client_id )    { if (!PL_get_chars(  arg, &client_id,          CVT_WRITE | BUF_MALLOC) ) { result = FALSE; goto CLEANUP;}
+            } else if ( name == ATOM_alias )        { if (!PL_get_chars(  arg, &alias,              CVT_WRITE | BUF_MALLOC) ) { result = FALSE; goto CLEANUP;}
 
             } else if ( name == ATOM_module )       { if (!PL_get_chars(  arg, &hook_module,        CVT_WRITE | BUF_MALLOC) ) { result = FALSE; goto CLEANUP;}
             } else if ( name == ATOM_on_log )       { if (!PL_get_chars(  arg, &hook_on_log,        CVT_WRITE | BUF_MALLOC) ) { result = FALSE; goto CLEANUP;}
@@ -986,7 +1006,7 @@ c_mqtt_connect(term_t conn, term_t host, term_t port, term_t options)
     
     if (is_async) {
       _LOG("--- (f-c) c_mqtt_connect > create prolog engine for async\n");
-      m->pl_engine = PL_create_engine(NULL);
+      m->pl_engine = PL_create_engine(get_callback_thread_attrs("th_callback_async"));
 
       _LOG("--- (f-c) c_mqtt_connect > connect async...\n");
       // with bind: rc = mosquitto_connect_bind_async(m->mosq, mqtt_host, mqtt_port, keepalive, NULL);
@@ -1231,7 +1251,7 @@ c_create_engine(void)
 {
   if (!current_engine)
   {
-    current_engine =  PL_create_engine(NULL); // PL_current_engine();
+    current_engine =  PL_create_engine(get_callback_thread_attrs("th_callback_gen")); // PL_current_engine();
     return TRUE;
   }
   return FALSE;
@@ -1261,6 +1281,7 @@ install_mqtt(void)
 
   ATOM_is_async       = PL_new_atom("is_async");
   ATOM_client_id      = PL_new_atom("client_id");
+  ATOM_alias          = PL_new_atom("alias");
   ATOM_keepalive      = PL_new_atom("keepalive");
   //ATOM_use_callbacks  = PL_new_atom("use_callbacks");
 
diff --git a/lib/x86_64-linux/mqtt.so b/lib/x86_64-linux/mqtt.so
index 30ed36e..aef8c85 100644
Binary files a/lib/x86_64-linux/mqtt.so and b/lib/x86_64-linux/mqtt.so differ