diff --git a/openmc/deplete/nuclide.py b/openmc/deplete/nuclide.py
index db503c8a59..a989bf7029 100644
--- a/openmc/deplete/nuclide.py
+++ b/openmc/deplete/nuclide.py
@@ -321,8 +321,8 @@ class Nuclide(object):
                 valid = False
 
         if self.yield_data:
-            for energy, yield_list in self.yield_data.items():
-                sum_yield = sum(y[1] for y in yield_list)
+            for energy, fission_yield in self.yield_data.items():
+                sum_yield = fission_yield.yields.sum()
                 stat = 2.0 - tolerance <= sum_yield <= 2.0 + tolerance
                 if stat:
                     continue
diff --git a/tests/unit_tests/test_deplete_chain.py b/tests/unit_tests/test_deplete_chain.py
index ce45b84d27..bdaf6c5ab1 100644
--- a/tests/unit_tests/test_deplete_chain.py
+++ b/tests/unit_tests/test_deplete_chain.py
@@ -377,7 +377,7 @@ def test_validate(simple_chain):
 
     # Fix fission yields but keep to restore later
     old_yields = simple_chain["C"].yield_data
-    simple_chain["C"].yield_data = {0.0253: [("A", 1.4), ("B", 0.6)]}
+    simple_chain["C"].yield_data = {0.0253: {"A": 1.4, "B": 0.6}}
 
     assert simple_chain.validate(strict=True, tolerance=0.0)
     with pytest.warns(None) as record:
diff --git a/tests/unit_tests/test_deplete_nuclide.py b/tests/unit_tests/test_deplete_nuclide.py
index d81691932b..6f5356b129 100644
--- a/tests/unit_tests/test_deplete_nuclide.py
+++ b/tests/unit_tests/test_deplete_nuclide.py
@@ -177,8 +177,8 @@ def test_validate():
     # fission yields
 
     nuc.yield_data = {
-        0.0253: [("0", 1.5), ("1", 0.5)],
-        1e6: [("0", 1.5), ("1", 0.5)],
+        0.0253: {"0": 1.5, "1": 0.5},
+        1e6: {"0": 1.5, "1": 0.5},
     }
 
     # nuclide is good and should have no warnings raise
@@ -212,7 +212,7 @@ def test_validate():
 
     # restore reactions, invalidate fission yields
     nuc.reactions.append(reaction)
-    nuc.yield_data[1e6].pop()
+    nuc.yield_data[1e6].yields *= 2
 
     with pytest.raises(ValueError, match=r"fission yields.*1\.0*e"):
         nuc.validate(strict=True, quiet=False, tolerance=0.0)