diff --git a/pymodbus/pdu/pdu.py b/pymodbus/pdu/pdu.py
index 431059f8c..8e09ccd5c 100644
--- a/pymodbus/pdu/pdu.py
+++ b/pymodbus/pdu/pdu.py
@@ -37,6 +37,7 @@ def __init__(self,
         self.registers: list[int] = registers or []
         self.count: int = count or len(self.registers)
         self.status: int = status
+        self.exception_code: int = 0
         self.fut: asyncio.Future
 
     def isError(self) -> bool: