diff --git a/ObservationSim/sim_steps/__init__.py b/ObservationSim/sim_steps/__init__.py
index e5ccadf0e2cc51491ac8be396a627056674fe894..0c928f6777dc750c18efa448bbed7a1ac5c29812 100644
--- a/ObservationSim/sim_steps/__init__.py
+++ b/ObservationSim/sim_steps/__init__.py
@@ -13,6 +13,7 @@ class SimSteps:
     from .add_pattern_noise import apply_PRNU, add_poisson_and_dark, add_detector_defects, add_nonlinearity, add_blooming, add_bias
     from .add_brighter_fatter_CTE import add_brighter_fatter, apply_CTE
     from .readout_output import add_prescan_overscan, add_readout_noise, apply_gain, quantization_and_output
+    from .add_LED_flat import add_LED_Flat
 
 SIM_STEP_TYPES = {
     "scie_obs": "add_objects",
diff --git a/ObservationSim/sim_steps/add_LED_flat.py b/ObservationSim/sim_steps/add_LED_flat.py
index b8a5ac2b16f834078835e828430cee10eb95fef0..85f1e9385fe169a065f3bd28e63d8afee92bb7c7 100644
--- a/ObservationSim/sim_steps/add_LED_flat.py
+++ b/ObservationSim/sim_steps/add_LED_flat.py
@@ -1,5 +1,6 @@
 import numpy as np
 from ObservationSim.MockObject import FlatLED
+import galsim
 
 def add_LED_Flat(self, chip, filt, tel, pointing, catalog, obs_param):
         
diff --git a/ObservationSim/sim_steps/add_sky_background.py b/ObservationSim/sim_steps/add_sky_background.py
index fc50878e150e038bc6b69f9d96d2ea135fb04324..aabcb162da92011edde9c43d76db56002caadebc 100644
--- a/ObservationSim/sim_steps/add_sky_background.py
+++ b/ObservationSim/sim_steps/add_sky_background.py
@@ -1,6 +1,7 @@
 import numpy as np
 import galsim
 from ObservationSim.Straylight import calculateSkyMap_split_g
+from ObservationSim.Instrument import FilterParam
 
 def add_sky_background_sci(self, chip, filt, tel, pointing, catalog, obs_param):
     flat_normal = np.ones_like(chip.img.array)