diff --git a/pymodbus/server/simulator/http_server.py b/pymodbus/server/simulator/http_server.py
index 537aaf8a1..82f74fef0 100644
--- a/pymodbus/server/simulator/http_server.py
+++ b/pymodbus/server/simulator/http_server.py
@@ -131,6 +131,8 @@ def __init__(
         if custom_actions_module:
             actions_module = importlib.import_module(custom_actions_module)
             custom_actions_dict = actions_module.custom_actions_dict
+        else:
+            custom_actions_dict = None
         server = setup["server_list"][modbus_server]
         server["loop"] = asyncio.get_running_loop()
         if server["comm"] != "serial":
@@ -502,8 +504,8 @@ async def build_json_server(self, params, json_dict):
 
     def helper_build_filter(self, params):
         """Build list of registers matching filter."""
-        range_start = params.get("range_start", -1)
-        range_stop = params.get("range_stop", range_start)
+        range_start = int(params.get("range_start", -1))
+        range_stop = int(params.get("range_stop", range_start))
         reg_action = int(params["action"])
         reg_writeable = "writeable" in params
         reg_type = int(params["type"])
diff --git a/pymodbus/server/simulator/main.py b/pymodbus/server/simulator/main.py
index 79961333b..09af4928a 100755
--- a/pymodbus/server/simulator/main.py
+++ b/pymodbus/server/simulator/main.py
@@ -109,6 +109,8 @@ def get_commandline():
 async def run_main():
     """Run server async."""
     cmd_args = get_commandline()
+    cmd_args["http_port"] = 8081
+    cmd_args["json_file"] = "./pymodbus/server/simulator/setup.json"
     task = ModbusSimulatorServer(**cmd_args)
     await task.run_forever()