diff --git a/kasa/iot/iotbulb.py b/kasa/iot/iotbulb.py
index 81d647e8..97826f2a 100644
--- a/kasa/iot/iotbulb.py
+++ b/kasa/iot/iotbulb.py
@@ -326,6 +326,7 @@ class IotBulb(IotDevice):
         self, state: dict, *, transition: int | None = None
     ) -> dict:
         """Set the light state."""
+        state = {**state}
         if transition is not None:
             state["transition_period"] = transition
 
diff --git a/kasa/iot/modules/light.py b/kasa/iot/modules/light.py
index 358771a6..c4d6cb09 100644
--- a/kasa/iot/modules/light.py
+++ b/kasa/iot/modules/light.py
@@ -230,6 +230,8 @@ class Light(IotModule, LightInterface):
                 state_dict["on_off"] = 1
             else:
                 state_dict["on_off"] = int(state.light_on)
+            # Remove the light_on from the dict
+            state_dict.pop("light_on", None)
             return await bulb._set_light_state(state_dict, transition=transition)
 
     @property
diff --git a/kasa/tests/test_bulb.py b/kasa/tests/test_bulb.py
index c78c539c..002cbd41 100644
--- a/kasa/tests/test_bulb.py
+++ b/kasa/tests/test_bulb.py
@@ -9,7 +9,7 @@ from voluptuous import (
     Schema,
 )
 
-from kasa import Device, DeviceType, IotLightPreset, KasaException, Module
+from kasa import Device, DeviceType, IotLightPreset, KasaException, LightState, Module
 from kasa.iot import IotBulb, IotDimmer
 
 from .conftest import (
@@ -96,6 +96,22 @@ async def test_set_hsv_transition(dev: IotBulb, mocker):
     )
 
 
+@bulb_iot
+async def test_light_set_state(dev: IotBulb, mocker):
+    """Testing setting LightState on the light module."""
+    light = dev.modules.get(Module.Light)
+    assert light
+    set_light_state = mocker.spy(dev, "_set_light_state")
+    state = LightState(light_on=True)
+    await light.set_state(state)
+
+    set_light_state.assert_called_with({"on_off": 1}, transition=None)
+    state = LightState(light_on=False)
+    await light.set_state(state)
+
+    set_light_state.assert_called_with({"on_off": 0}, transition=None)
+
+
 @color_bulb
 @turn_on
 async def test_invalid_hsv(dev: Device, turn_on):