diff --git a/requirements-deploy.txt b/requirements-deploy.txt
index 96b0350..2d1bf95 100644
--- a/requirements-deploy.txt
+++ b/requirements-deploy.txt
@@ -1,5 +1,5 @@
 # List external packages here
 # Avoid fixed versions
 # # to upload package to PyPi or other package hosts
-twine>=4.0.1,<5
+twine==6.*
 changelog2version>=0.5.0,<1
diff --git a/umodbus/const.py b/umodbus/const.py
index eb940be..7ba71de 100644
--- a/umodbus/const.py
+++ b/umodbus/const.py
@@ -104,6 +104,9 @@
 #: Modbus Application Protocol High Data Response length
 MBAP_HDR_LENGTH = const(0x07)
 
+#: Broadcast address
+BROADCAST_ADDR = const(0x00)
+
 #: CRC16 lookup table
 CRC16_TABLE = (
     0x0000, 0xC0C1, 0xC181, 0x0140, 0xC301, 0x03C0, 0x0280, 0xC241, 0xC601,
diff --git a/umodbus/serial.py b/umodbus/serial.py
index 11b8bee..67222c0 100644
--- a/umodbus/serial.py
+++ b/umodbus/serial.py
@@ -64,7 +64,7 @@ def __init__(self,
                    parity=parity,
                    pins=pins,
                    ctrl_pin=ctrl_pin),
-            [addr]
+            [Const.BROADCAST_ADDR, addr]
         )
 
 
@@ -292,7 +292,7 @@ def _send(self, modbus_pdu: bytes, slave_addr: int) -> None:
     def _send_receive(self,
                       modbus_pdu: bytes,
                       slave_addr: int,
-                      count: bool) -> bytes:
+                      count: bool) -> Union[bytes, None]:
         """
         Send a modbus message and receive the reponse.
 
@@ -311,6 +311,10 @@ def _send_receive(self,
 
         self._send(modbus_pdu=modbus_pdu, slave_addr=slave_addr)
 
+        if slave_addr == Const.BROADCAST_ADDR:
+            # Do not wait for response after a broadcast
+            return None
+
         return self._validate_resp_hdr(response=self._uart_read(),
                                        slave_addr=slave_addr,
                                        function_code=modbus_pdu[0],
@@ -386,6 +390,11 @@ def send_response(self,
         :param      signed:                 Indicates if signed
         :type       signed:                 bool
         """
+
+        if slave_addr == Const.BROADCAST_ADDR:
+            # Do not reply to broadcast messages
+            return
+
         modbus_pdu = functions.response(
             function_code=function_code,
             request_register_addr=request_register_addr,