diff --git a/openmc/data/fission_energy.py b/openmc/data/fission_energy.py
index 687cb5703e..83f61a1aec 100644
--- a/openmc/data/fission_energy.py
+++ b/openmc/data/fission_energy.py
@@ -24,7 +24,7 @@ def _extract_458_data(ev, units='eV'):
     ev : openmc.data.Evaluation
         ENDF evaluation
     units : {'eV', 'MeV'}
-        The units are used in values returned.
+        The units that are used in values returned.
 
     Returns
     -------