diff --git a/examples/optics/cavity_w_Rc.py b/examples/optics/cavity_w_Rc.py
index 8a5f60b61ad3c3e2a1dd480001d5dc7be25f7000..4b465c55454820aebb7ef5fd66ff4d5d7416ac3b 100644
--- a/examples/optics/cavity_w_Rc.py
+++ b/examples/optics/cavity_w_Rc.py
@@ -13,7 +13,7 @@ from __future__ import division
 from __future__ import print_function
 from __future__ import unicode_literals
 
-from pykat.optics.fabryperot import *
+from pykat.optics.fabry_perot import *
 import numpy as np
 
 
diff --git a/pykat/optics/FabryPerot.py b/pykat/optics/fabry_perot.py
similarity index 100%
rename from pykat/optics/FabryPerot.py
rename to pykat/optics/fabry_perot.py