diff --git a/swh/core/db/pytest_plugin.py b/swh/core/db/pytest_plugin.py
--- a/swh/core/db/pytest_plugin.py
+++ b/swh/core/db/pytest_plugin.py
@@ -4,6 +4,7 @@
 # See top-level LICENSE file for more information
 
 import glob
+from importlib import import_module
 import logging
 import subprocess
 from typing import List, Optional, Set, Union
@@ -11,15 +12,19 @@
 from _pytest.fixtures import FixtureRequest
 import psycopg2
 import pytest
-from pytest_postgresql.janitor import DatabaseJanitor, Version
+from pytest_postgresql.janitor import DatabaseJanitor
 
+from swh.core.utils import numfile_sortkey as sortkey
+
+# to keep mypy happy regardless pytest-postgresql version
 try:
-    from pytest_postgresql.config import get_config as _pytest_postgresql_get_config
+    _pytest_pgsql_get_config_module = import_module("pytest_postgresql.config")
 except ImportError:
     # pytest_postgresql < 3.0.0
-    from pytest_postgresql.factories import get_config as _pytest_postgresql_get_config
+    _pytest_pgsql_get_config_module = import_module("pytest_postgresql.factories")
+
+_pytest_postgresql_get_config = getattr(_pytest_pgsql_get_config_module, "get_config")
 
-from swh.core.utils import numfile_sortkey as sortkey
 
 logger = logging.getLogger(__name__)
 
@@ -40,14 +45,14 @@
         host: str,
         port: str,
         dbname: str,
-        version: Union[str, float, Version],
+        version: Union[str, float],
         dump_files: Union[None, str, List[str]] = None,
         no_truncate_tables: Set[str] = set(),
     ) -> None:
         super().__init__(user, host, port, dbname, version)
-        if not hasattr(self, "dbname"):
+        if not hasattr(self, "dbname") and hasattr(self, "db_name"):
             # pytest_postgresql < 3.0.0
-            self.dbname = self.db_name
+            self.dbname = getattr(self, "db_name")
         if dump_files is None:
             self.dump_files = []
         elif isinstance(dump_files, str):