diff --git a/src/mog_commons/__init__.py b/src/mog_commons/__init__.py
index b794fd4..df9144c 100644
--- a/src/mog_commons/__init__.py
+++ b/src/mog_commons/__init__.py
@@ -1 +1 @@
-__version__ = '0.1.0'
+__version__ = '0.1.1'
diff --git a/src/mog_commons/case_class.py b/src/mog_commons/case_class.py
index 811af7d..d4806a1 100644
--- a/src/mog_commons/case_class.py
+++ b/src/mog_commons/case_class.py
@@ -69,6 +69,18 @@ def __eq__(self, other):
     def __repr__(self):
         return '%s(%s)' % (self.__class__.__name__, ', '.join('%s=%r' % (k, getattr(self, k)) for k in self._keys))
 
+    def copy(self, **kwargs):
+        """
+        :param kwargs:
+        :return: copy of this object modifying the kwargs
+        """
+        for k in kwargs:
+            assert k in self._keys, 'Invalid key: %s' % k
+
+        d = self.values()
+        d.update(kwargs)
+        return self.__class__(**d)
+
     def values(self):
         """
         :return: key-value dict : { string: any }
diff --git a/tests/mog_commons/test_case_class.py b/tests/mog_commons/test_case_class.py
index af73682..5bae431 100644
--- a/tests/mog_commons/test_case_class.py
+++ b/tests/mog_commons/test_case_class.py
@@ -72,8 +72,16 @@ class AAA:
         self.assertRaisesRegexp(TypeError, '^unorderable types: Coord\(\) < ', lambda: Coord(123, 45) < 'x')
         self.assertRaisesRegexp(TypeError, '^unorderable types: Coord\(\) < AAA\(\)$', lambda: Coord(123, 45) < AAA())
 
-    def test_values(self):
-        self.assertEqual(Coord(123, 45).values(), {'x': 123, 'y': 45})
-
     def test_repr(self):
         self.assertEqual(repr(Coord(123, 45)), 'Coord(x=123, y=45)')
+
+    def test_copy(self):
+        a = Coord(123, 45)
+        b = a.copy(y=67)
+        self.assertEqual(b, Coord(123, 67))
+
+    def test_copy_error(self):
+        self.assertRaisesRegexp(AssertionError, 'Invalid key: z', Coord(123, 45).copy, x=999, z=999)
+
+    def test_values(self):
+        self.assertEqual(Coord(123, 45).values(), {'x': 123, 'y': 45})