diff --git a/common/config.py b/common/config.py
index 57f478c..71fabe1 100644
--- a/common/config.py
+++ b/common/config.py
@@ -37,17 +37,17 @@
                default=os.environ.get('OS_REGION_NAME'),
                help="The region name to us"),
     cfg.StrOpt('instance_type',
-               default='m1.micro',
+               default=os.environ.get('HEAT_TEST_INSTANCE_TYPE'),
                help="Instance type for tests. Needs to be big enough for a "
                     "full OS plus the test workload"),
     cfg.StrOpt('image_ref',
-               default='Fedora-x86_64-20-20140618-sda',
+               default=os.environ.get('HEAT_TEST_IMAGE_REF'),
                help="Name of image to use for tests which boot servers."),
     cfg.StrOpt('keypair_name',
                default=None,
                help="Name of existing keypair to launch servers with."),
     cfg.StrOpt('minimal_image_ref',
-               default='cirros-0.3.2-x86_64-uec',
+               default=os.environ.get('HEAT_TEST_MINIMAL_IMAGE_REF'),
                help="Name of minimal (e.g cirros) image to use when "
                     "launching test instances."),
     cfg.StrOpt('auth_version',