diff --git a/msrest/serialization.py b/msrest/serialization.py
index ee81c21578..547623adcf 100644
--- a/msrest/serialization.py
+++ b/msrest/serialization.py
@@ -191,7 +191,7 @@ class Serializer(object):
         "maximum_ex": lambda x, y: x >= y,
         "min_items": lambda x, y: len(x) < y,
         "max_items": lambda x, y: len(x) > y,
-        "pattern": lambda x, y: not re.match(y, x),
+        "pattern": lambda x, y: not re.match(y, x, re.UNICODE),
         "unique": lambda x, y: len(x) != len(set(x)),
         "multiple": lambda x, y: x % y != 0
         }
diff --git a/test/unittest_serialization.py b/test/unittest_serialization.py
index 166a375925..66be7bf825 100644
--- a/test/unittest_serialization.py
+++ b/test/unittest_serialization.py
@@ -158,6 +158,11 @@ def setUp(self):
         self.s = Serializer()
         return super(TestRuntimeSerialized, self).setUp()
 
+    def test_validate(self):
+        # Assert not necessary, should not raise exception
+        self.s.validate("simplestring", "StringForLog", pattern="^[a-z]+$")
+        self.s.validate(u"UTF8ééééé", "StringForLog", pattern=r"^[\w]+$")
+
     def test_obj_serialize_none(self):
         """Test that serialize None in object is still None.
         """