diff --git a/tests/storage/psql_dos/conftest.py b/tests/storage/psql_dos/conftest.py
index 16136b8df9..c24db0ac72 100644
--- a/tests/storage/psql_dos/conftest.py
+++ b/tests/storage/psql_dos/conftest.py
@@ -13,17 +13,12 @@
 from aiida.common.exceptions import MissingConfigurationError
 from aiida.manage.configuration import get_config
 
+STORAGE_BACKEND_ENTRY_POINT = None
 try:
     if test_profile := os.environ.get('AIIDA_TEST_PROFILE'):
         STORAGE_BACKEND_ENTRY_POINT = get_config().get_profile(test_profile).storage_backend
-    # TODO: The else branch is wrong
-    else:
-        STORAGE_BACKEND_ENTRY_POINT = 'core.psql_dos'
-except MissingConfigurationError:
-    # TODO: This is actually not true anymore!
-    # Case when ``pytest`` is invoked without existing config, in which case it will rely on the automatic test profile
-    # creation which currently always uses ``core.psql_dos`` for the storage backend
-    STORAGE_BACKEND_ENTRY_POINT = 'core.psql_dos'
+except MissingConfigurationError as e:
+    raise ValueError(f"Could not parse configuration of AiiDA test profile '{test_profile}'") from e
 
-if STORAGE_BACKEND_ENTRY_POINT != 'core.psql_dos':
+if STORAGE_BACKEND_ENTRY_POINT is not None and STORAGE_BACKEND_ENTRY_POINT != 'core.psql_dos':
     collect_ignore_glob = ['*']
diff --git a/tests/storage/psql_dos/migrations/django_branch/test_migrate_to_head.py b/tests/storage/psql_dos/migrations/django_branch/test_migrate_to_head.py
index 69c7e643d9..11f9fb8c3a 100644
--- a/tests/storage/psql_dos/migrations/django_branch/test_migrate_to_head.py
+++ b/tests/storage/psql_dos/migrations/django_branch/test_migrate_to_head.py
@@ -11,6 +11,15 @@
 from aiida.storage.psql_dos.migrator import PsqlDosMigrator
 
 
+def test_all_tests_marked_as_nightly(request):
+    """Test that all tests in this folder are tagged with 'nightly' marker"""
+    own_markers = [marker.name for marker in request.node.own_markers]
+
+    assert len(own_markers) == 2
+    assert 'nightly' in own_markers
+    assert 'requires_psql' in own_markers
+
+
 def test_migrate(perform_migrations: PsqlDosMigrator):
     """Test that the migrator can migrate from the base of the django branch, to the main head."""
     perform_migrations.migrate_up('django@django_0001')  # the base of the django branch
diff --git a/tests/storage/psql_dos/test_backend.py b/tests/storage/psql_dos/test_backend.py
index 6fe35ac747..bbc77b1a14 100644
--- a/tests/storage/psql_dos/test_backend.py
+++ b/tests/storage/psql_dos/test_backend.py
@@ -13,6 +13,14 @@
 from aiida.orm import User
 
 
+def test_all_tests_marked_with_requires_psql(request):
+    """Test that all tests in this folder are marked with 'requires_psql'"""
+    own_markers = [marker.name for marker in request.node.own_markers]
+
+    assert len(own_markers) == 1
+    assert own_markers[0] == 'requires_psql'
+
+
 @pytest.mark.usefixtures('aiida_profile_clean')
 def test_default_user():
     assert isinstance(get_manager().get_profile_storage().default_user, User)