diff --git a/qiita_db/test/test_util.py b/qiita_db/test/test_util.py
index e09a8c6fc..fddd44b9a 100644
--- a/qiita_db/test/test_util.py
+++ b/qiita_db/test/test_util.py
@@ -763,7 +763,7 @@ def test_generate_analysis_list(self):
         obs = qdb.util.generate_analysis_list([1, 2, 3, 5])
         exp = [{'mapping_files': [
                 (16, qdb.util.get_filepath_information(16)['fullpath'])],
-                'description': 'A test analysis', 'artifacts': [9], 'name':
+                'description': 'A test analysis', 'artifacts': [8, 9], 'name':
                 'SomeAnalysis', 'analysis_id': 1, 'visibility': 'private'},
                {'mapping_files': [], 'description': 'Another test analysis',
                 'artifacts': [], 'name': 'SomeSecondAnalysis',
diff --git a/qiita_db/util.py b/qiita_db/util.py
index e189fee83..67f39004a 100644
--- a/qiita_db/util.py
+++ b/qiita_db/util.py
@@ -1942,8 +1942,7 @@ def generate_analysis_list(analysis_ids, public_only=False):
 
     sql = """
         SELECT analysis_id, a.name, a.description, a.timestamp,
-            array_agg(DISTINCT CASE WHEN command_id IS NOT NULL
-                      THEN artifact_id END),
+            array_agg(DISTINCT artifact_id),
             array_agg(DISTINCT visibility),
             array_agg(DISTINCT CASE WHEN filepath_type = 'plain_text'
                       THEN filepath_id END)
diff --git a/qiita_ware/private_plugin.py b/qiita_ware/private_plugin.py
index c3e9aeb6a..de93fefba 100644
--- a/qiita_ware/private_plugin.py
+++ b/qiita_ware/private_plugin.py
@@ -316,10 +316,11 @@ def delete_study(job):
             _delete_analysis_artifacts(analysis)
 
         for pt in study.prep_templates():
-            to_delete = list(pt.artifact.descendants.nodes())
-            to_delete.reverse()
-            for td in to_delete:
-                qdb.artifact.Artifact.delete(td.id)
+            if pt.artifact:
+                to_delete = list(pt.artifact.descendants.nodes())
+                to_delete.reverse()
+                for td in to_delete:
+                    qdb.artifact.Artifact.delete(td.id)
             MT.prep_template.PrepTemplate.delete(pt.id)
 
         if MT.sample_template.SampleTemplate.exists(study_id):
diff --git a/qiita_ware/test/test_private_plugin.py b/qiita_ware/test/test_private_plugin.py
index 0cdc85644..af953375f 100644
--- a/qiita_ware/test/test_private_plugin.py
+++ b/qiita_ware/test/test_private_plugin.py
@@ -481,6 +481,26 @@ def test_delete_study_empty_study(self):
             "lab_person_id": StudyPerson(1)}
         new_study = Study.create(User('test@foo.bar'),
                                  "Fried Chicken Microbiome %s" % time(), info)
+        # creating a sample information file
+        metadata = pd.DataFrame.from_dict({
+            'Sample1': {'physical_specimen_location': 'location1',
+                        'taxon_id': '9606',
+                        'scientific_name': 'homo sapiens'},
+            'Sample2': {'physical_specimen_location': 'location1',
+                        'taxon_id': '9606',
+                        'scientific_name': 'homo sapiens'},
+            'Sample3': {'physical_specimen_location': 'location1',
+                        'taxon_id': '9606',
+                        'scientific_name': 'homo sapiens'}}, orient='index')
+        SampleTemplate.create(metadata, new_study)
+        # creating a preparation information file
+        metadata = pd.DataFrame.from_dict(
+            {'Sample1': {'center_name': 'ANL',
+                         'target_subfragment': 'V4',
+                         'center_project_name': 'Test Project'}},
+            orient='index', dtype=str)
+        PrepTemplate.create(metadata, new_study, '16S')
+
         job = self._create_job('delete_study', {'study': new_study.id})
         private_task(job.id)
         self.assertEqual(job.status, 'success')