diff --git a/CHANGELOG.md b/CHANGELOG.md
index 3bec3c5c..9c6525ef 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -9,6 +9,7 @@
 
 ### Fixed
 - `DynamicObstacle` cannot be hashed if some optional attributes are missing
+- `TrafficLightCycle` does not invalidate cached cycle init timesteps after modification
 
 ## [2024.2] - 2024-07-22
 
diff --git a/commonroad/scenario/traffic_light.py b/commonroad/scenario/traffic_light.py
index e46fc15a..d5856895 100644
--- a/commonroad/scenario/traffic_light.py
+++ b/commonroad/scenario/traffic_light.py
@@ -143,6 +143,9 @@ def cycle_elements(self) -> Union[None, List[TrafficLightCycleElement]]:
     @cycle_elements.setter
     def cycle_elements(self, cycle_elements: Union[None, List[TrafficLightCycleElement]]):
         self._cycle_elements = cycle_elements
+        # Invalidate cached attribute which was calculated based on the previous cycle elements
+        if hasattr(self, "_cycle_init_timesteps"):
+            del self._cycle_init_timesteps
 
     @property
     def time_offset(self) -> int:
@@ -152,6 +155,9 @@ def time_offset(self) -> int:
     @time_offset.setter
     def time_offset(self, time_offset: int):
         self._time_offset = time_offset
+        # Invalidate cached attribute which was calculated based on the previous time offset
+        if hasattr(self, "_cycle_init_timesteps"):
+            del self._cycle_init_timesteps
 
     @property
     def active(self) -> bool:
diff --git a/tests/scenario/test_traffic_light.py b/tests/scenario/test_traffic_light.py
index 547167d4..f01a63f6 100644
--- a/tests/scenario/test_traffic_light.py
+++ b/tests/scenario/test_traffic_light.py
@@ -82,6 +82,33 @@ def test_get_state_at_time_step(self):
         light_cycle2 = TrafficLightCycle(cycle_elements=cycle, time_offset=10)
         assert light_cycle2.get_state_at_time_step(12) == cycle[1].state
 
+    def test_update_cycle_elements(self):
+        # Verify that get_state_at_time_step is still correct after the cycle was updated
+        cycle = [
+            TrafficLightCycleElement(TrafficLightState.GREEN, 2),
+            TrafficLightCycleElement(TrafficLightState.YELLOW, 3),
+            TrafficLightCycleElement(TrafficLightState.RED, 2),
+        ]
+        light_cycle = TrafficLightCycle(cycle_elements=cycle, time_offset=0)
+        assert light_cycle.get_state_at_time_step(7) == cycle[0].state
+
+        new_cycle = cycle + [TrafficLightCycleElement(TrafficLightState.RED_YELLOW, 1)]
+        light_cycle.cycle_elements = new_cycle
+        assert light_cycle.get_state_at_time_step(7) == new_cycle[-1].state
+
+    def test_update_time_offset(self):
+        # Verify that get_state_at_time_step is still correct after the time offset was updated
+        cycle = [
+            TrafficLightCycleElement(TrafficLightState.GREEN, 2),
+            TrafficLightCycleElement(TrafficLightState.YELLOW, 3),
+            TrafficLightCycleElement(TrafficLightState.RED, 2),
+        ]
+        light_cycle = TrafficLightCycle(cycle_elements=cycle, time_offset=0)
+        assert light_cycle.get_state_at_time_step(1) == cycle[0].state
+
+        light_cycle.time_offset = 5
+        assert light_cycle.get_state_at_time_step(1) == cycle[1].state
+
 
 class TestTrafficLight(unittest.TestCase):
     def test_translate_rotate(self):