diff --git a/tests/test_calc.py b/tests/test_calc.py
index ef281f72bda4c790141438774f091001fd984339..70d77667295424cac61ce45388ddbb18bb7ed606 100644
--- a/tests/test_calc.py
+++ b/tests/test_calc.py
@@ -2,6 +2,7 @@
 # -*- coding: utf-8 -*-
 import unittest
 from os import path, listdir, curdir, remove
+import astropy
 
 from km3irf import Calculator
 from km3irf.utils import (