@@ -1377,6 +1377,10 @@ class EnergyFilter(RealFilter):
     """
     units = 'eV'
 
+    def __init__(self, values, filter_id=None):
+        cv.check_length('values', values, 2)
+        super().__init__(values, filter_id)
+
     def get_bin_index(self, filter_bin):
         # Use lower energy bound to find index for RealFilters
         deltas = np.abs(self.bins[:, 1] - filter_bin[1]) / filter_bin[1]
 
@@ -1,6 +1,6 @@
 import numpy as np
 import openmc
-from pytest import fixture, approx
+from pytest import fixture, approx, raises
 
 
 @fixture(scope='module')
@@ -248,6 +248,11 @@ def test_energy():
     assert len(f.values) == 710
 
 
+def test_energyfilter_error_handling():
+    with raises(ValueError):
+        openmc.EnergyFilter([1e6])
+
+
 def test_lethargy_bin_width():
     f = openmc.EnergyFilter.from_group_structure('VITAMIN-J-175')
     assert len(f.lethargy_bin_width) == 175