diff --git a/django/db/models/fields/__init__.py b/django/db/models/fields/__init__.py
index 91046f98c6..5d74e2002d 100644
--- a/django/db/models/fields/__init__.py
+++ b/django/db/models/fields/__init__.py
@@ -114,8 +114,8 @@ class Field(object):
         self.default = default
         self.editable = editable
         self.serialize = serialize
-        self.unique_for_date, self.unique_for_month = (unique_for_date,
-                                                       unique_for_month)
+        self.unique_for_date = unique_for_date
+        self.unique_for_month = unique_for_month
         self.unique_for_year = unique_for_year
         self._choices = choices or []
         self.help_text = help_text