diff --git a/pyproject.toml b/pyproject.toml
index 7b09479..28154e6 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -5,20 +5,22 @@ build-backend = "setuptools.build_meta"
 [project]
 name = "py-scopes"
 version = "3.0.1"
-description = "Implementation of the strange 'scopes' paradigma in Python"
+description = "Implementation of the unknown 'scopes' paradigm in Python"
 readme = "README.md"
 license = {text = "MIT"}
 keywords = ["scopes"]
 authors = [{name = "Helmut Merz", email = "helmutm@cy55.de"}]
 
 dependencies = [
+]
+
+[project.optional-dependencies]
+postgres = [
 	"transaction",
 	"psycopg[binary]",
 	"SQLAlchemy",
 	"zope.sqlalchemy",
 ]
-
-[project.optional-dependencies]
 app = ["python-dotenv", "zope.publisher", "zope.traversing"]
 test = ["pytest"]
 
diff --git a/scopes/storage/db/postgres.py b/scopes/storage/db/postgres.py
index 5fd0773..55e49b8 100644
--- a/scopes/storage/db/postgres.py
+++ b/scopes/storage/db/postgres.py
@@ -3,7 +3,7 @@
 """Database-related code specific for PostgreSQL."""
 
 from sqlalchemy import create_engine
-from sqlalchemy import BigInteger, JSONB
+from sqlalchemy import BigInteger
 from sqlalchemy.dialects.postgresql import JSONB
 from sqlalchemy.orm import scoped_session, sessionmaker
 import transaction
@@ -21,3 +21,12 @@ def getEngine(dbtype, dbname, user, pw, host='localhost', port=5432, **kw):
 
 def commit(conn):
     transaction.commit()
+
+import scopes.storage.common
+scopes.storage.common.IdType = BigInteger
+scopes.storage.common.JsonType = JSONB
+scopes.storage.common.sessionFactory = sessionFactory
+scopes.storage.common.getEngine = getEngine
+scopes.storage.common.mark_changed = mark_changed
+scopes.storage.common.commit = commit
+
diff --git a/tests/config.py b/tests/config.py
index 5ed3d8a..881dd13 100644
--- a/tests/config.py
+++ b/tests/config.py
@@ -9,6 +9,7 @@ app = zope_app
 # storage settings
 
 # PostgreSQL
+import scopes.storage.db.postgres
 dbengine = 'postgresql+psycopg'
 dbname = 'testdb'
 dbuser = 'testuser'
@@ -16,7 +17,7 @@ dbpassword = 'secret'
 dbschema = 'testing'
 
 # SQLite
-dbengine = 'sqlite'
-dbname = 'var/test.db'
-dbschema = None
+#dbengine = 'sqlite'
+#dbname = 'var/test.db'
+#dbschema = None
 
diff --git a/tests/test_storage.py b/tests/test_storage.py
index 8b2fbb6..59598bd 100644
--- a/tests/test_storage.py
+++ b/tests/test_storage.py
@@ -17,9 +17,7 @@ engine = getEngine(config.dbengine, config.dbname, config.dbuser, config.dbpassw
 scopes.storage.common.engine = engine
 scopes.storage.common.Session = sessionFactory(engine)
 
-#storage = Storage(schema='testing')
-#storage = Storage(schema=config.dbschema)
-storage = Storage()
+storage = Storage(schema=config.dbschema)
 
 
 class Test(unittest.TestCase):
@@ -86,8 +84,7 @@ class Test(unittest.TestCase):
         self.assertEqual(ch1.parent, top.rid)
         assert list(top.keys()) == ['child1']
 
-        #transaction.commit()
-        storage.session.commit()
+        commit(storage.session)
 
 def suite():
     return unittest.TestSuite((