diff --git a/ctapipe_io_magic/__init__.py b/ctapipe_io_magic/__init__.py
index 0344d12db3f8bf8d67680f1ac0858f8a75e879b9..0fdd2d6bb2ffc642a7106ca3180c71b2bc773872 100644
--- a/ctapipe_io_magic/__init__.py
+++ b/ctapipe_io_magic/__init__.py
@@ -860,6 +860,14 @@ class MarsRun:
                     pointing_ra = scipy.repeat(-1, len(mjd))
                     pointing_dec = scipy.repeat(-1, len(mjd))
 
+            # check for bit flips in the stereo event ID:
+            dx = np.diff(stereo_event_number)
+            for i in range(len(stereo_event_number)-1):
+                if (dx[i] > 1):
+                    print(i, stereo_event_number[i], dx[i])
+            dx_id_flip = np.where(dx < 0)[0]
+#            print("bit flips", len(dx_id_flip))
+
             event_data['charge'].append(charge)
             event_data['arrival_time'].append(arrival_time)
             event_data['badpixelinfo'].append(badpixelinfo)