diff --git a/pymodbus/client/mixin.py b/pymodbus/client/mixin.py
index a5c9d46d7..f91268cc1 100644
--- a/pymodbus/client/mixin.py
+++ b/pymodbus/client/mixin.py
@@ -927,7 +927,7 @@ def convert_from_registers(  # noqa: C901
         if not (data_len := data_type.value[1]):
             byte_list = bytearray()
             if word_order == "little":
-                registers.reverse()
+                registers = list(reversed(registers))
             for x in registers:
                 byte_list.extend(int.to_bytes(x, 2, "big"))
             if data_type == cls.DATATYPE.STRING:
diff --git a/test/client/test_client.py b/test/client/test_client.py
index faf791521..2128ae7ae 100755
--- a/test/client/test_client.py
+++ b/test/client/test_client.py
@@ -366,6 +366,34 @@ def test_client_mixin_convert_1234(self, datatype, registers, value):
         assert result == value
         assert regs == registers
 
+    @pytest.mark.parametrize("word_order", ["big", "little"])
+    @pytest.mark.parametrize(
+        ("datatype", "value"),
+        [
+            (ModbusClientMixin.DATATYPE.STRING, "Hello"),
+            (ModbusClientMixin.DATATYPE.STRING, "abcdefghij"),
+            (ModbusClientMixin.DATATYPE.BITS, [True, False, True] + [False] * 17),
+            (ModbusClientMixin.DATATYPE.INT32, 123456),
+            (ModbusClientMixin.DATATYPE.INT32, [1, 2, 3, 4]),
+        ],
+    )
+    def test_client_mixin_convert_from_registers_no_mutation(
+        self, datatype, value, word_order
+    ):
+        """convert_from_registers must not mutate input and stay deterministic."""
+        registers = ModbusClientMixin.convert_to_registers(
+            value, datatype, word_order=word_order
+        )
+        snapshot = list(registers)
+        first = ModbusClientMixin.convert_from_registers(
+            registers, datatype, word_order=word_order
+        )
+        assert registers == snapshot
+        second = ModbusClientMixin.convert_from_registers(
+            registers, datatype, word_order=word_order
+        )
+        assert first == second
+
     def test_client_mixin_convert_fail(self):
         """Test convert fail."""
         with pytest.raises(TypeError):