diff --git a/fuel_ccp/config/_yaml.py b/fuel_ccp/config/_yaml.py
index a1879104..b7eff311 100644
--- a/fuel_ccp/config/_yaml.py
+++ b/fuel_ccp/config/_yaml.py
@@ -65,7 +65,9 @@ class AttrDict(object):
                 value._merge(other_value)
             else:
                 if isinstance(other_value, dict):
-                    other_value = AttrDict(other_value)
+                    val = AttrDict()
+                    val._merge(other_value)
+                    other_value = val
                 self._dict[key] = other_value
 
     def _json(self, **kwargs):
diff --git a/fuel_ccp/tests/test_config.py b/fuel_ccp/tests/test_config.py
index dfdf23a4..68ac5d16 100644
--- a/fuel_ccp/tests/test_config.py
+++ b/fuel_ccp/tests/test_config.py
@@ -1,5 +1,6 @@
 import io
 import jsonschema
+import testscenarios
 
 from fuel_ccp import config
 from fuel_ccp.config import _yaml
@@ -26,3 +27,57 @@ class TestConfigSchema(base.TestCase):
         _yaml.dump(conf, stream)
         new_conf = _yaml.load(stream.getvalue())
         config.validate_config(new_conf)
+
+
+class TestAttrDict(testscenarios.WithScenarios, base.TestCase):
+    scenarios = (
+        ('empty_dict',
+            {'init_dict': {},
+             'value': {},
+             'res': _yaml.AttrDict()}),
+        ('one_value_dict',
+            {'init_dict': {},
+             'value': {'foo': True},
+             'res': _yaml.AttrDict({'foo': True})}),
+        ('nested_dict',
+            {'init_dict': {},
+             'value': {'bar': {'foo': True}},
+             'res': _yaml.AttrDict({'bar': _yaml.AttrDict({'foo': True})})}),
+        ('nested_nested_dict',
+            {'init_dict': {},
+             'value': {'baz': {'bar': {'foo': True}}},
+             'res': _yaml.AttrDict({'baz': _yaml.AttrDict({'bar':
+                                   _yaml.AttrDict({'foo': True})})})}),
+        ('merge_class',
+            {'init_dict': {},
+             'value': _yaml.AttrDict({'foo': 'bar'}),
+             'res': _yaml.AttrDict({'foo': 'bar'})}),
+        ('merge_class_same_val',
+            {'init_dict': {'foo': True},
+             'value': _yaml.AttrDict({'foo': 'bar'}),
+             'res': _yaml.AttrDict({'foo': 'bar'})}),
+        ('merge_dict_same_val',
+            {'init_dict': {'foo': True},
+             'value': {'foo': 'bar'},
+             'res': _yaml.AttrDict({'foo': 'bar'})}),
+        ('merge_nested_multi',
+            {'init_dict': {},
+             'value': {'baz': {'bar': {'foo': True}}, 'boom': {'cat': 'no'},
+                       'end': 'yes'},
+             'res': _yaml.AttrDict({'baz': {'bar': {'foo': True}},
+                                    'boom': {'cat': 'no'}, 'end': 'yes'})}),
+        ('merge_dict_diff_val',
+            {'init_dict': {'baz': True},
+             'value': {'foo': 'bar'},
+             'res': _yaml.AttrDict({'baz': True, 'foo': 'bar'})}),
+        ('merge_dict_mixed_val',
+            {'init_dict': {'baz': True, 'foo': False},
+             'value': {'foo': 'bar', 'cat': 'dog'},
+             'res': _yaml.AttrDict({'baz': True, 'cat': 'dog',
+                                    'foo': 'bar'})}),
+    )
+
+    def test_merge(self):
+        cls = _yaml.AttrDict(self.init_dict)
+        cls._merge(self.value)
+        self.assertEqual(self.res, cls)