diff --git a/sqlalchemy_utils/primitives/__init__.py b/sqlalchemy_utils/primitives/__init__.py
index f00f3ac..9a7dd90 100644
--- a/sqlalchemy_utils/primitives/__init__.py
+++ b/sqlalchemy_utils/primitives/__init__.py
@@ -1,7 +1,11 @@
 from .number_range import NumberRange, NumberRangeException
+from .weekday import WeekDay
+from .weekdays import WeekDays
 
 
 __all__ = (
     NumberRange,
-    NumberRangeException
+    NumberRangeException,
+    WeekDay,
+    WeekDays
 )
diff --git a/sqlalchemy_utils/primitives/utils.py b/sqlalchemy_utils/primitives/utils.py
new file mode 100644
index 0000000..4efed7b
--- /dev/null
+++ b/sqlalchemy_utils/primitives/utils.py
@@ -0,0 +1,13 @@
+import sys
+
+
+def str_coercible(cls):
+    if sys.version_info[0] >= 3:  # Python 3
+        def __str__(self):
+            return self.__unicode__()
+    else:  # Python 2
+        def __str__(self):
+            return self.__unicode__().encode('utf8')
+
+    cls.__str__ = __str__
+    return cls
diff --git a/sqlalchemy_utils/primitives/weekday.py b/sqlalchemy_utils/primitives/weekday.py
new file mode 100644
index 0000000..8c9e7a2
--- /dev/null
+++ b/sqlalchemy_utils/primitives/weekday.py
@@ -0,0 +1,63 @@
+# -*- coding: utf-8 -*-
+import sys
+from sqlalchemy import types
+from sqlalchemy.dialects.postgresql import BIT
+import six
+
+try:
+    from functools import total_ordering
+except ImportError:
+    # Python 2.6 port
+    from total_ordering import total_ordering
+from sqlalchemy_utils import i18n
+from .utils import str_coercible
+
+
+@str_coercible
+@total_ordering
+class WeekDay(object):
+    NUM_WEEK_DAYS = 7
+
+    def __init__(self, index):
+        if not (0 <= index < self.NUM_WEEK_DAYS):
+            raise ValueError(
+                "index must be between 0 and %d" % self.NUM_WEEK_DAYS
+            )
+        self.index = index
+
+    def __eq__(self, other):
+        if isinstance(other, WeekDay):
+            return self.index == other.index
+        else:
+            return NotImplemented
+
+    def __hash__(self):
+        return hash(self.index)
+
+    def __lt__(self, other):
+        return self.position < other.position
+
+    def __repr__(self):
+        return '%s(%r)' % (self.__class__.__name__, self.index)
+
+    def __unicode__(self):
+        return self.name
+
+    def get_name(self, width='wide', context='format'):
+        names = i18n.get_day_names(
+            width,
+            context,
+            i18n.get_locale()
+        )
+        return names[self.index]
+
+    @property
+    def name(self):
+        return self.get_name()
+
+    @property
+    def position(self):
+        return (
+            self.index -
+            i18n.get_locale().first_week_day
+        ) % self.NUM_WEEK_DAYS
diff --git a/sqlalchemy_utils/primitives/weekdays.py b/sqlalchemy_utils/primitives/weekdays.py
new file mode 100644
index 0000000..b8dffb7
--- /dev/null
+++ b/sqlalchemy_utils/primitives/weekdays.py
@@ -0,0 +1,60 @@
+import six
+
+from .utils import str_coercible
+from .weekday import WeekDay
+
+
+@str_coercible
+class WeekDays(object):
+    def __init__(self, bit_string_or_week_days):
+        if isinstance(bit_string_or_week_days, six.string_types):
+            self._days = set()
+
+            if len(bit_string_or_week_days) != WeekDay.NUM_WEEK_DAYS:
+                raise ValueError(
+                    'Bit string must be {0} characters long.'.format(
+                        WeekDay.NUM_WEEK_DAYS
+                    )
+                )
+
+            for index, bit in enumerate(bit_string_or_week_days):
+                if bit not in '01':
+                    raise ValueError(
+                        'Bit string may only contain zeroes and ones.'
+                    )
+                if bit == '1':
+                    self._days.add(WeekDay(index))
+        elif isinstance(bit_string_or_week_days, WeekDays):
+            self._days = bit_string_or_week_days._days
+        else:
+            self._days = set(bit_string_or_week_days)
+
+    def __eq__(self, other):
+        if isinstance(other, WeekDays):
+            return self._days == other._days
+        elif isinstance(other, six.string_types):
+            return self.as_bit_string() == other
+        else:
+            return NotImplemented
+
+    def __iter__(self):
+        for day in sorted(self._days):
+            yield day
+
+    def __contains__(self, value):
+        return value in self._days
+
+    def __repr__(self):
+        return '%s(%r)' % (
+            self.__class__.__name__,
+            self.as_bit_string()
+        )
+
+    def __unicode__(self):
+        return u', '.join(six.text_type(day) for day in self)
+
+    def as_bit_string(self):
+        return ''.join(
+            '1' if WeekDay(index) in self._days else '0'
+            for index in six.moves.xrange(WeekDay.NUM_WEEK_DAYS)
+        )
diff --git a/sqlalchemy_utils/types/weekdays.py b/sqlalchemy_utils/types/weekdays.py
index 753e9d2..505988c 100644
--- a/sqlalchemy_utils/types/weekdays.py
+++ b/sqlalchemy_utils/types/weekdays.py
@@ -1,133 +1,7 @@
-# -*- coding: utf-8 -*-
-import sys
+import six
 from sqlalchemy import types
 from sqlalchemy.dialects.postgresql import BIT
-import six
-
-try:
-    from functools import total_ordering
-except ImportError:
-    # Python 2.6 port
-    from total_ordering import total_ordering
-from sqlalchemy_utils import i18n
-
-
-@total_ordering
-class WeekDay(object):
-    NUM_WEEK_DAYS = 7
-
-    def __init__(self, index):
-        if not (0 <= index < self.NUM_WEEK_DAYS):
-            raise ValueError(
-                "index must be between 0 and %d" % self.NUM_WEEK_DAYS
-            )
-        self.index = index
-
-    def __eq__(self, other):
-        if isinstance(other, WeekDay):
-            return self.index == other.index
-        else:
-            return NotImplemented
-
-    def __hash__(self):
-        return hash(self.index)
-
-    def __lt__(self, other):
-        return self.position < other.position
-
-    def __repr__(self):
-        return '%s(%r)' % (self.__class__.__name__, self.index)
-
-    if sys.version_info[0] >= 3:  # Python 3
-        def __str__(self):
-            return self.__unicode__()
-    else:  # Python 2
-        def __str__(self):
-            return self.__unicode__().encode('utf8')
-
-    def __unicode__(self):
-        return self.name
-
-    def get_name(self, width='wide', context='format'):
-        names = i18n.get_day_names(
-            width,
-            context,
-            i18n.get_locale()
-        )
-        return names[self.index]
-
-    @property
-    def name(self):
-        return self.get_name()
-
-    @property
-    def position(self):
-        return (
-            self.index -
-            i18n.get_locale().first_week_day
-        ) % self.NUM_WEEK_DAYS
-
-
-class WeekDays(object):
-    def __init__(self, bit_string_or_week_days):
-        if isinstance(bit_string_or_week_days, six.string_types):
-            self._days = set()
-
-            if len(bit_string_or_week_days) != WeekDay.NUM_WEEK_DAYS:
-                raise ValueError(
-                    'Bit string must be {0} characters long.'.format(
-                        WeekDay.NUM_WEEK_DAYS
-                    )
-                )
-
-            for index, bit in enumerate(bit_string_or_week_days):
-                if bit not in '01':
-                    raise ValueError(
-                        'Bit string may only contain zeroes and ones.'
-                    )
-                if bit == '1':
-                    self._days.add(WeekDay(index))
-        elif isinstance(bit_string_or_week_days, WeekDays):
-            self._days = bit_string_or_week_days._days
-        else:
-            self._days = set(bit_string_or_week_days)
-
-    def __eq__(self, other):
-        if isinstance(other, WeekDays):
-            return self._days == other._days
-        elif isinstance(other, six.string_types):
-            return self.as_bit_string() == other
-        else:
-            return NotImplemented
-
-    def __iter__(self):
-        for day in sorted(self._days):
-            yield day
-
-    def __contains__(self, value):
-        return value in self._days
-
-    def __repr__(self):
-        return '%s(%r)' % (
-            self.__class__.__name__,
-            self.as_bit_string()
-        )
-
-    if sys.version_info[0] >= 3:  # Python 3
-        def __str__(self):
-            return self.__unicode__()
-    else:  # Python 2
-        def __str__(self):
-            return self.__unicode__().encode('utf8')
-
-    def __unicode__(self):
-        return u', '.join(six.text_type(day) for day in self)
-
-    def as_bit_string(self):
-        return ''.join(
-            '1' if WeekDay(index) in self._days else '0'
-            for index in six.moves.xrange(WeekDay.NUM_WEEK_DAYS)
-        )
+from sqlalchemy_utils.primitives import WeekDay, WeekDays
 
 
 class WeekDaysType(types.TypeDecorator):
diff --git a/tests/primitives/test_weekdays.py b/tests/primitives/test_weekdays.py
index 21168ee..70f5681 100644
--- a/tests/primitives/test_weekdays.py
+++ b/tests/primitives/test_weekdays.py
@@ -81,6 +81,11 @@ class TestWeekDay(object):
         flexmock(day).should_receive('name').and_return(u'maanantaina')
         assert six.text_type(day) == u'maanantaina'
 
+    def test_str(self):
+        day = WeekDay(0)
+        flexmock(day).should_receive('name').and_return(u'maanantaina')
+        assert str(day) == 'maanantaina'
+
 
 @pytest.mark.skipif('Locale is None')
 class TestWeekDays(object):
@@ -158,3 +163,8 @@ class TestWeekDays(object):
         i18n.get_locale = lambda: Locale('fi')
         days = WeekDays('1000100')
         assert six.text_type(days) == u'maanantaina, perjantaina'
+
+    def test_str(self):
+        i18n.get_locale = lambda: Locale('fi')
+        days = WeekDays('1000100')
+        assert str(days) == 'maanantaina, perjantaina'