diff --git a/watcher/metrics_engine/cluster_history/api.py b/watcher/metrics_engine/cluster_history/base.py
similarity index 100%
rename from watcher/metrics_engine/cluster_history/api.py
rename to watcher/metrics_engine/cluster_history/base.py
diff --git a/watcher/metrics_engine/cluster_history/ceilometer.py b/watcher/metrics_engine/cluster_history/ceilometer.py
index a2d946960..56b29ddad 100644
--- a/watcher/metrics_engine/cluster_history/ceilometer.py
+++ b/watcher/metrics_engine/cluster_history/ceilometer.py
@@ -22,13 +22,13 @@ from oslo_config import cfg
 from oslo_log import log
 from watcher.common import ceilometer_helper
 
-from watcher.metrics_engine.cluster_history import api
+from watcher.metrics_engine.cluster_history import base
 
 CONF = cfg.CONF
 LOG = log.getLogger(__name__)
 
 
-class CeilometerClusterHistory(api.BaseClusterHistory):
+class CeilometerClusterHistory(base.BaseClusterHistory):
     def __init__(self, osc=None):
         """:param osc: an OpenStackClients instance"""
         super(CeilometerClusterHistory, self).__init__()
diff --git a/watcher/metrics_engine/cluster_model_collector/api.py b/watcher/metrics_engine/cluster_model_collector/base.py
similarity index 100%
rename from watcher/metrics_engine/cluster_model_collector/api.py
rename to watcher/metrics_engine/cluster_model_collector/base.py
diff --git a/watcher/metrics_engine/cluster_model_collector/nova.py b/watcher/metrics_engine/cluster_model_collector/nova.py
index 23443aca0..b3ac3e827 100644
--- a/watcher/metrics_engine/cluster_model_collector/nova.py
+++ b/watcher/metrics_engine/cluster_model_collector/nova.py
@@ -23,12 +23,12 @@ from watcher.decision_engine.model import hypervisor as obj_hypervisor
 from watcher.decision_engine.model import model_root
 from watcher.decision_engine.model import resource
 from watcher.decision_engine.model import vm as obj_vm
-from watcher.metrics_engine.cluster_model_collector import api
+from watcher.metrics_engine.cluster_model_collector import base
 
 LOG = log.getLogger(__name__)
 
 
-class NovaClusterModelCollector(api.BaseClusterModelCollector):
+class NovaClusterModelCollector(base.BaseClusterModelCollector):
     def __init__(self, wrapper):
         super(NovaClusterModelCollector, self).__init__()
         self.wrapper = wrapper
diff --git a/watcher/tests/decision_engine/strategy/strategies/faker_cluster_state.py b/watcher/tests/decision_engine/strategy/strategies/faker_cluster_state.py
index a5e46beff..5514d4f2a 100644
--- a/watcher/tests/decision_engine/strategy/strategies/faker_cluster_state.py
+++ b/watcher/tests/decision_engine/strategy/strategies/faker_cluster_state.py
@@ -20,10 +20,10 @@ from watcher.decision_engine.model import hypervisor
 from watcher.decision_engine.model import model_root as modelroot
 from watcher.decision_engine.model import resource
 from watcher.decision_engine.model import vm as modelvm
-from watcher.metrics_engine.cluster_model_collector import api
+from watcher.metrics_engine.cluster_model_collector import base
 
 
-class FakerModelCollector(api.BaseClusterModelCollector):
+class FakerModelCollector(base.BaseClusterModelCollector):
     def __init__(self):
         pass