diff --git a/tests/unit_test/app_common/aggregators/in_time_accumulate_weighted_aggregator_test.py b/tests/unit_test/app_common/aggregators/in_time_accumulate_weighted_aggregator_test.py
index e96c81ea5f..3f5ae02e4c 100644
--- a/tests/unit_test/app_common/aggregators/in_time_accumulate_weighted_aggregator_test.py
+++ b/tests/unit_test/app_common/aggregators/in_time_accumulate_weighted_aggregator_test.py
@@ -72,11 +72,14 @@ class TestInTimeAccumulateWeightedAggregator:
     )
     def test_invalid_create(self, exclude_vars, aggregation_weights, expected_data_kind, error, error_msg):
         with pytest.raises(error, match=re.escape(error_msg)):
-            _ = InTimeAccumulateWeightedAggregator(
+            aggregator = InTimeAccumulateWeightedAggregator(
                 exclude_vars=exclude_vars,
                 aggregation_weights=aggregation_weights,
                 expected_data_kind=expected_data_kind,
             )
+            aggregator._initialize(
+                aggregator.aggregation_weights, aggregator.exclude_vars, aggregator.expected_data_kind
+            )
 
     @pytest.mark.parametrize(
         "exclude_vars,aggregation_weights,expected_data_kind,expected_object",
@@ -115,9 +118,13 @@ def test_invalid_create(self, exclude_vars, aggregation_weights, expected_data_k
         ],
     )
     def test_create(self, exclude_vars, aggregation_weights, expected_data_kind, expected_object):
+        expected_object._initialize(
+            expected_object.aggregation_weights, expected_object.exclude_vars, expected_object.expected_data_kind
+        )
         result = InTimeAccumulateWeightedAggregator(
             exclude_vars=exclude_vars, aggregation_weights=aggregation_weights, expected_data_kind=expected_data_kind
         )
+        result._initialize(result.aggregation_weights, result.exclude_vars, result.expected_data_kind)
         assert result.exclude_vars == expected_object.exclude_vars
         assert result.aggregation_weights == expected_object.aggregation_weights
         assert result.expected_data_kind == expected_object.expected_data_kind
@@ -126,6 +133,7 @@ def test_create(self, exclude_vars, aggregation_weights, expected_data_kind, exp
     def test_accept(self, current_round, contribution_round, expected):
         aggregation_weights = {f"client_{i}": random.random() for i in range(2)}
         agg = InTimeAccumulateWeightedAggregator(aggregation_weights=aggregation_weights)
+        agg._initialize(agg.aggregation_weights, agg.exclude_vars, agg.expected_data_kind)
         client_name = "client_0"
         iter_number = 1
         weights = np.random.random(4)
@@ -192,6 +200,7 @@ def test_accept(self, current_round, contribution_round, expected):
     def test_aggregate(self, received, expected):
         aggregation_weights = {k: v["weight"] for k, v in received.items()}
         agg = InTimeAccumulateWeightedAggregator(aggregation_weights=aggregation_weights)
+        agg._initialize(agg.aggregation_weights, agg.exclude_vars, agg.expected_data_kind)
         fl_ctx = FLContext()
         fl_ctx.set_prop(AppConstants.CURRENT_ROUND, 0)
         for k, v in received.items():
@@ -216,6 +225,7 @@ def test_aggregate(self, received, expected):
     def test_aggregate_random(self, shape, n_clients):
         aggregation_weights = {f"client_{i}": random.random() for i in range(n_clients)}
         agg = InTimeAccumulateWeightedAggregator(aggregation_weights=aggregation_weights)
+        agg._initialize(agg.aggregation_weights, agg.exclude_vars, agg.expected_data_kind)
         weighted_sum = np.zeros(shape)
         sum_of_weights = 0
         fl_ctx = FLContext()
@@ -254,6 +264,7 @@ def test_aggregate_random_dxos(self, num_dxo, shape, n_clients):
             aggregation_weights=aggregation_weights,
             expected_data_kind={dxo_name: DataKind.WEIGHT_DIFF for dxo_name in dxo_names},
         )
+        agg._initialize(agg.aggregation_weights, agg.exclude_vars, agg.expected_data_kind)
         weighted_sum = {dxo_name: np.zeros(shape) for dxo_name in dxo_names}
         sum_of_weights = {dxo_name: 0 for dxo_name in dxo_names}
         fl_ctx = FLContext()