diff --git a/test/hca_metadata_api/test.py b/test/hca_metadata_api/test.py
index 50dc71a8e..dadbefd6a 100644
--- a/test/hca_metadata_api/test.py
+++ b/test/hca_metadata_api/test.py
@@ -518,7 +518,7 @@ def test_imaging_protocol(self):
         version = '2019-04-03T103426.471000Z'
         manifest, metadata_files = self._canned_bundle('staging', uuid, version)
         bundle = Bundle(uuid, version, manifest, metadata_files)
-        imaging_protocol = one([p for p in bundle.protocols.values() if isinstance(p, ImagingProtocol)])
+        imaging_protocol = one(p for p in bundle.protocols.values() if isinstance(p, ImagingProtocol))
         self.assertEqual(len(imaging_protocol.probe), 240)
         assay_types = {probe.assay_type for probe in imaging_protocol.probe}
         self.assertEqual(assay_types, {'in situ sequencing'})
@@ -547,7 +547,7 @@ def test_links_json_v2_0_0(self):
         manifest, metadata_files = self._canned_bundle('prod', uuid, version)
         bundle = Bundle(uuid, version, manifest, metadata_files)
         for expected_count, link_type in [(6, 'process_link'), (2, 'supplementary_file_link')]:
-            actual_count = sum([1 for link in bundle.links if link.link_type == link_type])
+            actual_count = sum(1 for link in bundle.links if link.link_type == link_type)
             self.assertEqual(expected_count, actual_count)
         for link in bundle.links:
             self.assertIn(link.source_type, api_entity_types)
diff --git a/test/indexer/test_indexer.py b/test/indexer/test_indexer.py
index b7997641d..84843c0df 100644
--- a/test/indexer/test_indexer.py
+++ b/test/indexer/test_indexer.py
@@ -1597,7 +1597,7 @@ def test_cell_line_sample(self):
                     document_ids = one(contents[sample_entity_type])['document_id']
                 else:
                     document_ids = [d['document_id'] for d in contents[sample_entity_type]]
-                    entity = one([d for d in contents[sample_entity_type] if d['document_id'] == sample['document_id']])
+                    entity = one(d for d in contents[sample_entity_type] if d['document_id'] == sample['document_id'])
                     self.assertEqual(sample['biomaterial_id'], entity['biomaterial_id'])
                 self.assertTrue(sample['document_id'] in document_ids)
                 self.assertEqual(one(contents['specimens'])['organ'], ['blood'] if aggregate else 'blood')
diff --git a/test/service/test_manifest.py b/test/service/test_manifest.py
index 1587a7c0f..0ab15e689 100644
--- a/test/service/test_manifest.py
+++ b/test/service/test_manifest.py
@@ -1048,7 +1048,7 @@ def _extract_bdbag_response(self,
             self.assertEqual(200, response.status_code)
             with ZipFile(BytesIO(response.content), 'r') as zip_fh:
                 zip_fh.extractall(zip_dir)
-                self.assertTrue(all(['manifest' == first(name.split('/')) for name in zip_fh.namelist()]))
+                self.assertTrue(all('manifest' == first(name.split('/')) for name in zip_fh.namelist()))
                 zip_fname = os.path.dirname(first(zip_fh.namelist()))
             with open(os.path.join(zip_dir, zip_fname, 'data', 'participants.tsv'), 'r') as fh:
                 reader = csv.DictReader(fh, delimiter='\t')