diff --git a/tests/unit_tests/test_source.py b/tests/unit_tests/test_source.py
index f186437e4..dbcf49efc 100644
--- a/tests/unit_tests/test_source.py
+++ b/tests/unit_tests/test_source.py
@@ -1,6 +1,6 @@
 import openmc
 import openmc.stats
-from math import pi, cos
+from math import pi
 
 def test_source():
     space = openmc.stats.Point()