diff --git a/ceilometer/storage/impl_hbase.py b/ceilometer/storage/impl_hbase.py
index 2c491d18..f83ee0d8 100644
--- a/ceilometer/storage/impl_hbase.py
+++ b/ceilometer/storage/impl_hbase.py
@@ -310,6 +310,8 @@ class Connection(hbase_base.Connection, base.Connection):
                                    limit=limit, columns=columns)
             for ignored, meter in gen:
                 d_meter = hbase_utils.deserialize_entry(meter)[0]
+                d_meter['message']['counter_volume'] = (
+                    float(d_meter['message']['counter_volume']))
                 d_meter['message']['recorded_at'] = d_meter['recorded_at']
                 yield models.Sample(**d_meter['message'])
 
diff --git a/ceilometer/storage/mongo/utils.py b/ceilometer/storage/mongo/utils.py
index 6a1efc9c..08fc7768 100644
--- a/ceilometer/storage/mongo/utils.py
+++ b/ceilometer/storage/mongo/utils.py
@@ -48,7 +48,7 @@ OP_SIGN = {'lt': '$lt', 'le': '$lte', 'ne': '$ne', 'gt': '$gt', 'ge': '$gte'}
 MINIMUM_COMPATIBLE_MONGODB_VERSION = [2, 4]
 COMPLETE_AGGREGATE_COMPATIBLE_VERSION = [2, 6]
 
-TRIVIAL_LAMBDA = lambda result, param=None: result
+FINALIZE_AGGREGATION_LAMBDA = lambda result, param=None: float(result)
 CARDINALITY_VALIDATION = (lambda name, param: param in ['resource_id',
                                                         'user_id',
                                                         'project_id',
@@ -519,7 +519,7 @@ class AggregationFields(object):
                  finalize=None,
                  parametrized=False,
                  validate=None):
-        self._finalize = finalize or TRIVIAL_LAMBDA
+        self._finalize = finalize or FINALIZE_AGGREGATION_LAMBDA
         self.group = lambda *args: group(*args) if parametrized else group
         self.project = (lambda *args: project(*args)
                         if parametrized else project)
diff --git a/ceilometer/storage/pymongo_base.py b/ceilometer/storage/pymongo_base.py
index 365339b4..93c696d5 100644
--- a/ceilometer/storage/pymongo_base.py
+++ b/ceilometer/storage/pymongo_base.py
@@ -139,6 +139,8 @@ class Connection(base.Connection):
             del s['_id']
             # Backward compatibility for samples without units
             s['counter_unit'] = s.get('counter_unit', '')
+            # Compatibility with MongoDB 3.+
+            s['counter_volume'] = float(s.get('counter_volume'))
             # Tolerate absence of recorded_at in older datapoints
             s['recorded_at'] = s.get('recorded_at')
             # Check samples for metadata and "unquote" key if initially it
diff --git a/ceilometer/tests/functional/storage/test_storage_scenarios.py b/ceilometer/tests/functional/storage/test_storage_scenarios.py
index 611b01af..a86dd2e1 100644
--- a/ceilometer/tests/functional/storage/test_storage_scenarios.py
+++ b/ceilometer/tests/functional/storage/test_storage_scenarios.py
@@ -406,6 +406,13 @@ class RawSampleTest(DBTestBase,
             source='test-4'
         ))
 
+    def test_get_sample_counter_volume(self):
+        # NOTE(idegtiarov) Because wsme expected a float type of data this test
+        # checks type of counter_volume received from database.
+        f = storage.SampleFilter()
+        result = next(self.conn.get_samples(f, limit=1))
+        self.assertIsInstance(result.counter_volume, float)
+
     def test_get_samples_limit_zero(self):
         f = storage.SampleFilter()
         results = list(self.conn.get_samples(f, limit=0))