diff --git a/losscalculator/damage_calculator.py b/losscalculator/damage_calculator.py
index 725441f9dc9c8b673a460aee0136718f44327738..f482524a27cf127a37c44ac024b16d580285eaa5 100644
--- a/losscalculator/damage_calculator.py
+++ b/losscalculator/damage_calculator.py
@@ -23,7 +23,8 @@ import numpy as np
 import pandas as pd
 import losslib
 import datetime
-import FragilityModel
+
+from .fragility_model import FragilityModel
 
 
 def damage_calculator(
@@ -53,7 +54,7 @@ def damage_calculator(
     # Read inputs.
     gm_field = np.loadtxt(gm_field_filepath, delimiter=",", skiprows=1)
     exposure = pd.read_csv(exposure_filepath)
-    fragility_model = FragilityModel.FragilityModel(
+    fragility_model = FragilityModel(
         fragility_filepath,
         gm_field_filepath,
         intensity_measure_map_filepath,
diff --git a/losscalculator/FragilityModel.py b/losscalculator/fragility_model.py
similarity index 100%
rename from losscalculator/FragilityModel.py
rename to losscalculator/fragility_model.py
diff --git a/tests/test_lossCalculator.py b/tests/test_losscalculator.py
similarity index 100%
rename from tests/test_lossCalculator.py
rename to tests/test_losscalculator.py