diff --git a/oslo_db/sqlalchemy/models.py b/oslo_db/sqlalchemy/models.py
index 0c4e0de..0467971 100644
--- a/oslo_db/sqlalchemy/models.py
+++ b/oslo_db/sqlalchemy/models.py
@@ -23,10 +23,12 @@ SQLAlchemy models.
 import six
 
 from oslo_utils import timeutils
-from sqlalchemy import Column, Integer
+from sqlalchemy import Column
 from sqlalchemy import DateTime
 from sqlalchemy.orm import object_mapper
 
+from oslo_db.sqlalchemy import types
+
 
 class ModelBase(six.Iterator):
     """Base class for models."""
@@ -139,7 +141,7 @@ class TimestampMixin(object):
 
 class SoftDeleteMixin(object):
     deleted_at = Column(DateTime)
-    deleted = Column(Integer, default=0)
+    deleted = Column(types.SoftDeleteInteger, default=0)
 
     def soft_delete(self, session):
         """Mark this object as deleted."""
diff --git a/oslo_db/sqlalchemy/types.py b/oslo_db/sqlalchemy/types.py
index a6f8acb..f74f909 100644
--- a/oslo_db/sqlalchemy/types.py
+++ b/oslo_db/sqlalchemy/types.py
@@ -12,7 +12,7 @@
 
 import json
 
-from sqlalchemy.types import TypeDecorator, Text
+from sqlalchemy.types import Integer, TypeDecorator, Text
 from sqlalchemy.dialects import mysql
 
 
@@ -73,3 +73,20 @@ class JsonEncodedList(JsonEncodedType):
     http://docs.sqlalchemy.org/en/rel_1_0/orm/extensions/mutable.html
     """
     type = list
+
+
+class SoftDeleteInteger(TypeDecorator):
+    """Coerce a bound param to be a proper integer before passing it to DBAPI.
+
+    Some backends like PostgreSQL are very strict about types and do not
+    perform automatic type casts, e.g. when trying to INSERT a boolean value
+    like ``false`` into an integer column. Coercing of the bound param in DB
+    layer by the means of a custom SQLAlchemy type decorator makes sure we
+    always pass a proper integer value to a DBAPI implementation.
+
+    """
+
+    impl = Integer
+
+    def process_bind_param(self, value, dialect):
+        return int(value)
diff --git a/oslo_db/tests/sqlalchemy/test_models.py b/oslo_db/tests/sqlalchemy/test_models.py
index 60e8c55..fc12b0b 100644
--- a/oslo_db/tests/sqlalchemy/test_models.py
+++ b/oslo_db/tests/sqlalchemy/test_models.py
@@ -14,10 +14,13 @@
 #    under the License.
 
 import collections
+import datetime
 
+import mock
 from oslotest import base as oslo_test
 from sqlalchemy import Column
 from sqlalchemy import Integer, String
+from sqlalchemy import event
 from sqlalchemy.ext.declarative import declarative_base
 
 from oslo_db.sqlalchemy import models
@@ -179,3 +182,50 @@ class TimestampMixinTest(oslo_test.BaseTestCase):
         for method in methods:
             self.assertTrue(hasattr(models.TimestampMixin, method),
                             "Method %s() is not found" % method)
+
+
+class SoftDeletedModel(BASE, models.ModelBase, models.SoftDeleteMixin):
+    __tablename__ = 'test_model_soft_deletes'
+
+    id = Column('id', Integer, primary_key=True)
+    smth = Column('smth', String(255))
+
+
+class SoftDeleteMixinTest(test_base.DbTestCase):
+    def setUp(self):
+        super(SoftDeleteMixinTest, self).setUp()
+
+        t = BASE.metadata.tables['test_model_soft_deletes']
+        t.create(self.engine)
+        self.addCleanup(t.drop, self.engine)
+
+        self.session = self.sessionmaker(autocommit=False)
+        self.addCleanup(self.session.close)
+
+    @mock.patch('oslo_utils.timeutils.utcnow')
+    def test_soft_delete(self, mock_utcnow):
+        dt = datetime.datetime.utcnow().replace(microsecond=0)
+        mock_utcnow.return_value = dt
+
+        m = SoftDeletedModel(id=123456, smth='test')
+        self.session.add(m)
+        self.session.commit()
+        self.assertEqual(0, m.deleted)
+        self.assertIs(None, m.deleted_at)
+
+        m.soft_delete(self.session)
+        self.assertEqual(123456, m.deleted)
+        self.assertIs(dt, m.deleted_at)
+
+    def test_soft_delete_coerce_deleted_to_integer(self):
+        def listener(conn, cur, stmt, params, context, executemany):
+            if 'insert' in stmt.lower():  # ignore SELECT 1 and BEGIN
+                self.assertNotIn('False', str(params))
+
+        event.listen(self.engine, 'before_cursor_execute', listener)
+        self.addCleanup(event.remove,
+                        self.engine, 'before_cursor_execute', listener)
+
+        m = SoftDeletedModel(id=1, smth='test', deleted=False)
+        self.session.add(m)
+        self.session.commit()