diff --git a/openmc/filter.py b/openmc/filter.py
index 2af5fe5b79..35a65f4fef 100644
--- a/openmc/filter.py
+++ b/openmc/filter.py
@@ -1913,6 +1913,8 @@ class EnergyFunctionFilter(Filter):
     def __eq__(self, other):
         if type(self) is not type(other):
             return False
+        elif not self.interpolation == other.interpolation:
+            return False
         elif not all(self.energy == other.energy):
             return False
         else: