diff --git a/voluptuous/tests/tests.py b/voluptuous/tests/tests.py
index 9d784bd..28598f7 100644
--- a/voluptuous/tests/tests.py
+++ b/voluptuous/tests/tests.py
@@ -67,24 +67,24 @@ def test_iterate_candidates():
 
 def test_in():
     """Verify that In works."""
-    schema = Schema({"color": In(frozenset(["blue", "red", "yellow"]))})
+    schema = Schema({"color": In(frozenset(["red", "blue", "yellow"]))})
     schema({"color": "blue"})
     try:
         schema({"color": "orange"})
     except Invalid as e:
-        assert_equal(str(e), "value is not allowed for dictionary value @ data['color']")
+        assert_equal(str(e), "value must be one of ['blue', 'red', 'yellow'] for dictionary value @ data['color']")
     else:
         assert False, "Did not raise InInvalid"
 
 
 def test_not_in():
     """Verify that NotIn works."""
-    schema = Schema({"color": NotIn(frozenset(["blue", "red", "yellow"]))})
+    schema = Schema({"color": NotIn(frozenset(["red", "blue", "yellow"]))})
     schema({"color": "orange"})
     try:
         schema({"color": "blue"})
     except Invalid as e:
-        assert_equal(str(e), "value is not allowed for dictionary value @ data['color']")
+        assert_equal(str(e), "value must not be one of ['blue', 'red', 'yellow'] for dictionary value @ data['color']")
     else:
         assert False, "Did not raise NotInInvalid"
 
diff --git a/voluptuous/validators.py b/voluptuous/validators.py
index fd0aa90..5e9a932 100644
--- a/voluptuous/validators.py
+++ b/voluptuous/validators.py
@@ -738,7 +738,7 @@ def __call__(self, v):
             check = True
         if check:
             raise InInvalid(self.msg or 
-                            'value must be one of {}'.format(self.container))
+                            'value must be one of {}'.format(sorted(self.container)))
         return v
 
     def __repr__(self):
@@ -759,7 +759,7 @@ def __call__(self, v):
             check = True
         if check:
             raise NotInInvalid(self.msg or 
-                               'value must not be one of {}'.format(self.container))
+                               'value must not be one of {}'.format(sorted(self.container)))
         return v
 
     def __repr__(self):