diff --git a/src/ModbusRTU.cpp b/src/ModbusRTU.cpp
index a00d609..695ff67 100644
--- a/src/ModbusRTU.cpp
+++ b/src/ModbusRTU.cpp
@@ -309,6 +309,7 @@ void ModbusRTUTemplate::task() {
     free(_frame);
     _frame = nullptr;
     _len = 0;
+	_slaveId = 0;
 	if (isMaster) cleanup();
 }