diff --git a/src/lerobot/cameras/opencv/camera_opencv.py b/src/lerobot/cameras/opencv/camera_opencv.py
index 3e92eaf06..b3c20e8dd 100644
--- a/src/lerobot/cameras/opencv/camera_opencv.py
+++ b/src/lerobot/cameras/opencv/camera_opencv.py
@@ -442,11 +442,12 @@ class OpenCVCamera(Camera):
 
         Stops on DeviceNotConnectedError, logs other errors and continues.
         """
-        if self.stop_event is None:
+        stop_event = self.stop_event
+        if stop_event is None:
             raise RuntimeError(f"{self}: stop_event is not initialized before starting read loop.")
 
         failure_count = 0
-        while not self.stop_event.is_set():
+        while not stop_event.is_set():
             try:
                 raw_frame = self._read_from_hardware()
                 processed_frame = self._postprocess_image(raw_frame)
diff --git a/src/lerobot/cameras/realsense/camera_realsense.py b/src/lerobot/cameras/realsense/camera_realsense.py
index e156e6d14..80008e9f9 100644
--- a/src/lerobot/cameras/realsense/camera_realsense.py
+++ b/src/lerobot/cameras/realsense/camera_realsense.py
@@ -471,11 +471,12 @@ class RealSenseCamera(Camera):
 
         Stops on DeviceNotConnectedError, logs other errors and continues.
         """
-        if self.stop_event is None:
+        stop_event = self.stop_event
+        if stop_event is None:
             raise RuntimeError(f"{self}: stop_event is not initialized before starting read loop.")
 
         failure_count = 0
-        while not self.stop_event.is_set():
+        while not stop_event.is_set():
             try:
                 frame = self._read_from_hardware()
                 color_frame_raw = frame.get_color_frame()
diff --git a/src/lerobot/cameras/zmq/camera_zmq.py b/src/lerobot/cameras/zmq/camera_zmq.py
index 1b0be5de6..f3df17814 100644
--- a/src/lerobot/cameras/zmq/camera_zmq.py
+++ b/src/lerobot/cameras/zmq/camera_zmq.py
@@ -246,11 +246,12 @@ class ZMQCamera(Camera):
         """
         Internal loop run by the background thread for asynchronous reading.
         """
-        if self.stop_event is None:
+        stop_event = self.stop_event
+        if stop_event is None:
             raise RuntimeError(f"{self}: stop_event is not initialized.")
 
         failure_count = 0
-        while not self.stop_event.is_set():
+        while not stop_event.is_set():
             try:
                 frame = self._read_from_hardware()
                 capture_time = time.perf_counter()