diff --git a/tox.ini b/tox.ini
index 30b9e3b828..8ae74446c8 100644
--- a/tox.ini
+++ b/tox.ini
@@ -7,12 +7,6 @@ envlist = py27,py34,pep8
 usedevelop = True
 install_command = pip install -U {opts} {packages}
 setenv = VIRTUAL_ENV={envdir}
-         # NOTE(viktors): we must change default connection string for MySQL
-         # because we are use PyMySQL as a DB connector, but opportunistic
-         # migration tests uses MySQLdb by default.
-         # TODO(viktors): Remove this evn variable, when Ironic will use
-         # oslo.db>=1.12.0
-         OS_TEST_DBAPI_ADMIN_CONNECTION=mysql+pymysql://openstack_citest:openstack_citest@localhost/;postgresql://openstack_citest:openstack_citest@localhost/postgres;sqlite://
          PYTHONDONTWRITEBYTECODE = 1
          LANGUAGE=en_US
 deps = -r{toxinidir}/requirements.txt