diff --git a/ctapipe_io_lst/__init__.py b/ctapipe_io_lst/__init__.py
index b5cf63af..f7381478 100644
--- a/ctapipe_io_lst/__init__.py
+++ b/ctapipe_io_lst/__init__.py
@@ -21,7 +21,7 @@
 
 from ctapipe.io import EventSource
 from ctapipe.io.datalevels import DataLevel
-from ctapipe.core.traits import Int, Bool, List, Float, Enum
+from ctapipe.core.traits import Int, Bool, Float, Enum
 from ctapipe.containers import PixelStatusContainer, EventType
 
 from .containers import LSTArrayEventContainer, LSTServiceContainer
@@ -37,7 +37,7 @@
     TIB_DTYPE,
 )
 from .constants import (
-    HIGH_GAIN, N_PIXELS, N_MODULES, N_SAMPLES
+    HIGH_GAIN, N_PIXELS, N_SAMPLES
 )
 
 __all__ = ['LSTEventSource', '__version__']
diff --git a/ctapipe_io_lst/calibration.py b/ctapipe_io_lst/calibration.py
index 697b85ad..91a2adc8 100644
--- a/ctapipe_io_lst/calibration.py
+++ b/ctapipe_io_lst/calibration.py
@@ -13,7 +13,7 @@
 )
 
 from ctapipe.calib.camera.gainselection import ThresholdGainSelector
-from ctapipe.containers import MonitoringContainer, ArrayEventContainer, EventType
+from ctapipe.containers import MonitoringContainer, ArrayEventContainer
 from ctapipe.io import HDF5TableReader
 
 
diff --git a/ctapipe_io_lst/constants.py b/ctapipe_io_lst/constants.py
index a2cc67fa..225dd6c0 100644
--- a/ctapipe_io_lst/constants.py
+++ b/ctapipe_io_lst/constants.py
@@ -1,6 +1,3 @@
-import numpy as np
-
-
 N_GAINS = 2
 N_MODULES = 265
 N_PIXELS_MODULE = 7
diff --git a/ctapipe_io_lst/containers.py b/ctapipe_io_lst/containers.py
index 17d850e6..2902fc45 100644
--- a/ctapipe_io_lst/containers.py
+++ b/ctapipe_io_lst/containers.py
@@ -4,7 +4,7 @@
 from astropy import units as u
 from numpy import nan
 from ctapipe.core import Container, Field, Map
-from ctapipe.containers import ArrayEventContainer, MonitoringContainer
+from ctapipe.containers import ArrayEventContainer
 
 
 __all__ = [
diff --git a/ctapipe_io_lst/tests/test_event_time.py b/ctapipe_io_lst/tests/test_event_time.py
index 79a134f4..059854fe 100644
--- a/ctapipe_io_lst/tests/test_event_time.py
+++ b/ctapipe_io_lst/tests/test_event_time.py
@@ -1,4 +1,3 @@
-from ctapipe_io_lst import event_time
 import os
 from pathlib import Path
 import numpy as np