diff --git a/Modbus/IO/ModbusRtuTransport.cs b/Modbus/IO/ModbusRtuTransport.cs
index 9955783..8563d89 100644
--- a/Modbus/IO/ModbusRtuTransport.cs
+++ b/Modbus/IO/ModbusRtuTransport.cs
@@ -66,7 +66,8 @@ public static int ResponseBytesToRead(byte[] frameStart)
                 Modbus.ReadCoils or
                 Modbus.ReadInputs or
                 Modbus.ReadHoldingRegisters or
-                Modbus.ReadInputRegisters
+                Modbus.ReadInputRegisters or
+                Modbus.ReadWriteMultipleRegisters
                     => frameStart[2] + 1,
 
                 Modbus.WriteSingleCoil or
@@ -134,4 +135,4 @@ internal override byte[] ReadRequest()
 
         return frame;
     }
-}
\ No newline at end of file
+}
diff --git a/Modbus/Message/AbstractModbusMessage.cs b/Modbus/Message/AbstractModbusMessage.cs
index cf689ab..4c96960 100644
--- a/Modbus/Message/AbstractModbusMessage.cs
+++ b/Modbus/Message/AbstractModbusMessage.cs
@@ -39,7 +39,7 @@ public byte SlaveAddress
         set => MessageImpl.SlaveAddress = value;
     }
 
-    public byte[] MessageFrame =>
+    public virtual byte[] MessageFrame =>
         MessageImpl.MessageFrame;
 
     public virtual byte[] ProtocolDataUnit =>
@@ -62,4 +62,4 @@ public void Initialize(byte[] frame)
     }
 
     protected abstract void InitializeUnique(byte[] frame);
-}
\ No newline at end of file
+}
diff --git a/Modbus/Message/ReadWriteMultipleRegistersRequest.cs b/Modbus/Message/ReadWriteMultipleRegistersRequest.cs
index 5de8923..c0afb71 100644
--- a/Modbus/Message/ReadWriteMultipleRegistersRequest.cs
+++ b/Modbus/Message/ReadWriteMultipleRegistersRequest.cs
@@ -28,6 +28,20 @@ public ReadWriteMultipleRegistersRequest(
             writeData);
     }
 
+    public override byte[] MessageFrame
+    {
+        get
+        {
+            byte[]? pdu = ProtocolDataUnit;
+            MemoryStream frame = new(1 + pdu.Length);
+
+            frame.WriteByte(SlaveAddress);
+            frame.Write(pdu, 0, pdu.Length);
+
+            return frame.ToArray();
+        }
+    }
+
     public override byte[] ProtocolDataUnit
     {
         get
@@ -86,4 +100,4 @@ protected override void InitializeUnique(byte[] frame)
         ReadRequest = ModbusMessageFactory.CreateModbusMessage<ReadHoldingInputRegistersRequest>(readFrame);
         WriteRequest = ModbusMessageFactory.CreateModbusMessage<WriteMultipleRegistersRequest>(writeFrame);
     }
-}
\ No newline at end of file
+}