diff --git a/openmc/filter.py b/openmc/filter.py
index d83b9f6ba..d6571cd5a 100644
--- a/openmc/filter.py
+++ b/openmc/filter.py
@@ -2095,7 +2095,7 @@ class EnergyFunctionFilter(Filter):
         y = [float(x) for x in get_text(elem, 'y').split()]
         out = cls(energy, y, filter_id=filter_id)
         if elem.find('interpolation') is not None:
-            out.interpolation = elem.find('interpolation')
+            out.interpolation = elem.find('interpolation').text
         return out
 
     def can_merge(self, other):
diff --git a/tests/unit_tests/test_filters.py b/tests/unit_tests/test_filters.py
index a20b129e9..8a6f095ef 100644
--- a/tests/unit_tests/test_filters.py
+++ b/tests/unit_tests/test_filters.py
@@ -254,3 +254,18 @@ def test_lethargy_bin_width():
     energy_bins = openmc.mgxs.GROUP_STRUCTURES['VITAMIN-J-175']
     assert f.lethargy_bin_width[0] == np.log10(energy_bins[1]/energy_bins[0])
     assert f.lethargy_bin_width[-1] == np.log10(energy_bins[-1]/energy_bins[-2])
+
+
+def test_energyfunc():
+    f = openmc.EnergyFunctionFilter(
+        [0.0, 10.0, 2.0e3, 1.0e6, 20.0e6],
+        [1.0, 0.9, 0.8, 0.7, 0.6],
+        'histogram'
+    )
+
+    # Make sure XML roundtrip works
+    elem = f.to_xml_element()
+    new_f = openmc.EnergyFunctionFilter.from_xml_element(elem)
+    np.testing.assert_allclose(f.energy, new_f.energy)
+    np.testing.assert_allclose(f.y, new_f.y)
+    assert f.interpolation == new_f.interpolation