diff --git a/pymodbus/register_write_message.py b/pymodbus/register_write_message.py
index 4ff21ac9c..b49db4901 100644
--- a/pymodbus/register_write_message.py
+++ b/pymodbus/register_write_message.py
@@ -132,9 +132,11 @@ def __init__(self, address=None, values=None, **kwargs):
         '''
         ModbusRequest.__init__(self, **kwargs)
         self.address = address
-        self.values = values or []
-        if not hasattr(values, '__iter__'):
-            self.values = [values]
+        if values is None:
+            values = []
+        elif not hasattr(values, '__iter__'):
+            values = [values]
+        self.values = values
         self.count = len(self.values)
         self.byte_count = self.count * 2