diff --git a/google/cloud/aiplatform/base.py b/google/cloud/aiplatform/base.py
index 868431fbdc..e88de02934 100644
--- a/google/cloud/aiplatform/base.py
+++ b/google/cloud/aiplatform/base.py
@@ -1,6 +1,6 @@
 # -*- coding: utf-8 -*-
 
-# Copyright 2020 Google LLC
+# Copyright 2022 Google LLC
 #
 # Licensed under the Apache License, Version 2.0 (the "License");
 # you may not use this file except in compliance with the License.
@@ -1077,9 +1077,11 @@ def _list(
             or initializer.global_config.common_location_path(
                 project=project, location=location
             ),
-            "filter": filter,
         }
 
+        if filter:
+            list_request["filter"] = filter
+
         if order_by:
             list_request["order_by"] = order_by
 
diff --git a/tests/unit/aiplatform/test_datasets.py b/tests/unit/aiplatform/test_datasets.py
index 2a912d47dd..2b81c04251 100644
--- a/tests/unit/aiplatform/test_datasets.py
+++ b/tests/unit/aiplatform/test_datasets.py
@@ -1421,9 +1421,7 @@ def test_list_dataset_no_order_or_filter(self, list_datasets_mock):
 
         ds_list = aiplatform.TabularDataset.list()
 
-        list_datasets_mock.assert_called_once_with(
-            request={"parent": _TEST_PARENT, "filter": None}
-        )
+        list_datasets_mock.assert_called_once_with(request={"parent": _TEST_PARENT})
 
         # Ensure returned list is smaller since it filtered out non-tabular datasets
         assert len(ds_list) < len(_TEST_DATASET_LIST)
diff --git a/tests/unit/aiplatform/test_featurestores.py b/tests/unit/aiplatform/test_featurestores.py
index 014a2442bd..08d57be0c5 100644
--- a/tests/unit/aiplatform/test_featurestores.py
+++ b/tests/unit/aiplatform/test_featurestores.py
@@ -984,7 +984,7 @@ def test_list_featurestores(self, list_featurestores_mock):
         my_featurestore_list = aiplatform.Featurestore.list()
 
         list_featurestores_mock.assert_called_once_with(
-            request={"parent": _TEST_PARENT, "filter": None}
+            request={"parent": _TEST_PARENT}
         )
         assert len(my_featurestore_list) == len(_TEST_FEATURESTORE_LIST)
         for my_featurestore in my_featurestore_list:
@@ -1028,7 +1028,7 @@ def test_list_entity_types(self, list_entity_types_mock):
         my_entity_type_list = my_featurestore.list_entity_types()
 
         list_entity_types_mock.assert_called_once_with(
-            request={"parent": _TEST_FEATURESTORE_NAME, "filter": None}
+            request={"parent": _TEST_FEATURESTORE_NAME}
         )
         assert len(my_entity_type_list) == len(_TEST_ENTITY_TYPE_LIST)
         for my_entity_type in my_entity_type_list:
@@ -1770,7 +1770,7 @@ def test_list_entity_types(self, featurestore_name, list_entity_types_mock):
         )
 
         list_entity_types_mock.assert_called_once_with(
-            request={"parent": _TEST_FEATURESTORE_NAME, "filter": None}
+            request={"parent": _TEST_FEATURESTORE_NAME}
         )
         assert len(my_entity_type_list) == len(_TEST_ENTITY_TYPE_LIST)
         for my_entity_type in my_entity_type_list:
@@ -1784,7 +1784,7 @@ def test_list_features(self, list_features_mock):
         my_feature_list = my_entity_type.list_features()
 
         list_features_mock.assert_called_once_with(
-            request={"parent": _TEST_ENTITY_TYPE_NAME, "filter": None}
+            request={"parent": _TEST_ENTITY_TYPE_NAME}
         )
         assert len(my_feature_list) == len(_TEST_FEATURE_LIST)
         for my_feature in my_feature_list:
@@ -2851,7 +2851,7 @@ def test_list_features(self, entity_type_name, featurestore_id, list_features_mo
         )
 
         list_features_mock.assert_called_once_with(
-            request={"parent": _TEST_ENTITY_TYPE_NAME, "filter": None}
+            request={"parent": _TEST_ENTITY_TYPE_NAME}
         )
         assert len(my_feature_list) == len(_TEST_FEATURE_LIST)
         for my_feature in my_feature_list:
diff --git a/tests/unit/aiplatform/test_matching_engine_index.py b/tests/unit/aiplatform/test_matching_engine_index.py
index 78e3a608a9..98943fdfb7 100644
--- a/tests/unit/aiplatform/test_matching_engine_index.py
+++ b/tests/unit/aiplatform/test_matching_engine_index.py
@@ -246,9 +246,7 @@ def test_list_indexes(self, list_indexes_mock):
 
         my_indexes_list = aiplatform.MatchingEngineIndex.list()
 
-        list_indexes_mock.assert_called_once_with(
-            request={"parent": _TEST_PARENT, "filter": None}
-        )
+        list_indexes_mock.assert_called_once_with(request={"parent": _TEST_PARENT})
         assert len(my_indexes_list) == len(_TEST_INDEX_LIST)
         for my_index in my_indexes_list:
             assert type(my_index) == aiplatform.MatchingEngineIndex
diff --git a/tests/unit/aiplatform/test_matching_engine_index_endpoint.py b/tests/unit/aiplatform/test_matching_engine_index_endpoint.py
index 58ff16ed56..231ab20ae0 100644
--- a/tests/unit/aiplatform/test_matching_engine_index_endpoint.py
+++ b/tests/unit/aiplatform/test_matching_engine_index_endpoint.py
@@ -440,7 +440,7 @@ def test_list_index_endpoints(self, list_index_endpoints_mock):
         my_index_endpoints_list = aiplatform.MatchingEngineIndexEndpoint.list()
 
         list_index_endpoints_mock.assert_called_once_with(
-            request={"parent": _TEST_PARENT, "filter": None}
+            request={"parent": _TEST_PARENT}
         )
         assert len(my_index_endpoints_list) == len(_TEST_INDEX_ENDPOINT_LIST)
         for my_index_endpoint in my_index_endpoints_list:
diff --git a/tests/unit/aiplatform/test_models.py b/tests/unit/aiplatform/test_models.py
index fdd22bfe96..e71d257fc0 100644
--- a/tests/unit/aiplatform/test_models.py
+++ b/tests/unit/aiplatform/test_models.py
@@ -2382,7 +2382,7 @@ def test_get_model_evaluation_without_id(
         test_model.get_model_evaluation()
 
         list_model_evaluations_mock.assert_called_once_with(
-            request={"parent": _TEST_MODEL_RESOURCE_NAME, "filter": None}
+            request={"parent": _TEST_MODEL_RESOURCE_NAME}
         )
 
     def test_list_model_evaluations(
@@ -2397,7 +2397,7 @@ def test_list_model_evaluations(
         eval_list = test_model.list_model_evaluations()
 
         list_model_evaluations_mock.assert_called_once_with(
-            request={"parent": _TEST_MODEL_RESOURCE_NAME, "filter": None}
+            request={"parent": _TEST_MODEL_RESOURCE_NAME}
         )
 
         assert len(eval_list) == len(_TEST_MODEL_EVAL_LIST)
diff --git a/tests/unit/aiplatform/test_pipeline_jobs.py b/tests/unit/aiplatform/test_pipeline_jobs.py
index 63c09ac799..9975fedd5c 100644
--- a/tests/unit/aiplatform/test_pipeline_jobs.py
+++ b/tests/unit/aiplatform/test_pipeline_jobs.py
@@ -1289,7 +1289,7 @@ def test_list_pipeline_job(
         job.list()
 
         mock_pipeline_service_list.assert_called_once_with(
-            request={"parent": _TEST_PARENT, "filter": None}
+            request={"parent": _TEST_PARENT}
         )
 
     @pytest.mark.usefixtures(
diff --git a/tests/unit/aiplatform/test_tensorboard.py b/tests/unit/aiplatform/test_tensorboard.py
index b73b805202..7a999905ea 100644
--- a/tests/unit/aiplatform/test_tensorboard.py
+++ b/tests/unit/aiplatform/test_tensorboard.py
@@ -735,7 +735,7 @@ def test_list_tensorboard_experiments(self, list_tensorboard_experiment_mock):
         tensorboard.TensorboardExperiment.list(tensorboard_name=_TEST_NAME)
 
         list_tensorboard_experiment_mock.assert_called_once_with(
-            request={"parent": _TEST_NAME, "filter": None}
+            request={"parent": _TEST_NAME}
         )
 
 
@@ -785,7 +785,7 @@ def test_init_tensorboard_run_with_id_only_with_project_and_location(
             name=_TEST_TENSORBOARD_RUN_NAME, retry=base._DEFAULT_RETRY
         )
         list_tensorboard_time_series_mock.assert_called_once_with(
-            request={"parent": _TEST_TENSORBOARD_RUN_NAME, "filter": None}
+            request={"parent": _TEST_TENSORBOARD_RUN_NAME}
         )
 
     @pytest.mark.usefixtures("list_tensorboard_time_series_mock")
@@ -900,11 +900,11 @@ def test_list_tensorboard_runs(
         )
 
         list_tensorboard_run_mock.assert_called_once_with(
-            request={"parent": _TEST_TENSORBOARD_EXPERIMENT_NAME, "filter": None}
+            request={"parent": _TEST_TENSORBOARD_EXPERIMENT_NAME}
         )
 
         list_tensorboard_time_series_mock.assert_called_once_with(
-            request={"parent": _TEST_TENSORBOARD_RUN_NAME, "filter": None}
+            request={"parent": _TEST_TENSORBOARD_RUN_NAME}
         )
 
     @pytest.mark.usefixtures(
@@ -1064,5 +1064,5 @@ def test_list_tensorboard_time_series(self, list_tensorboard_time_series_mock):
         )
 
         list_tensorboard_time_series_mock.assert_called_once_with(
-            request={"parent": _TEST_TENSORBOARD_RUN_NAME, "filter": None}
+            request={"parent": _TEST_TENSORBOARD_RUN_NAME}
         )