diff --git a/django/contrib/admin/widgets.py b/django/contrib/admin/widgets.py
index 0d1f2a9ff7..29958b27a4 100644
--- a/django/contrib/admin/widgets.py
+++ b/django/contrib/admin/widgets.py
@@ -53,8 +53,11 @@ class AdminDateWidget(forms.DateInput):
         js = ["calendar.js", "admin/DateTimeShortcuts.js"]
         return forms.Media(js=[static("admin/js/%s" % path) for path in js])
 
-    def __init__(self, attrs={}, format=None):
-        super(AdminDateWidget, self).__init__(attrs={'class': 'vDateField', 'size': '10'}, format=format)
+    def __init__(self, attrs=None, format=None):
+        final_attrs = {'class': 'vDateField', 'size': '10'}
+        if attrs is not None:
+            final_attrs.update(attrs)
+        super(AdminDateWidget, self).__init__(attrs=final_attrs, format=format)
 
 class AdminTimeWidget(forms.TimeInput):
 
@@ -63,8 +66,11 @@ class AdminTimeWidget(forms.TimeInput):
         js = ["calendar.js", "admin/DateTimeShortcuts.js"]
         return forms.Media(js=[static("admin/js/%s" % path) for path in js])
 
-    def __init__(self, attrs={}, format=None):
-        super(AdminTimeWidget, self).__init__(attrs={'class': 'vTimeField', 'size': '8'}, format=format)
+    def __init__(self, attrs=None, format=None):
+        final_attrs = {'class': 'vTimeField', 'size': '8'}
+        if attrs is not None:
+            final_attrs.update(attrs)
+        super(AdminTimeWidget, self).__init__(attrs=final_attrs, format=format)
 
 class AdminSplitDateTime(forms.SplitDateTimeWidget):
     """
diff --git a/tests/regressiontests/admin_widgets/tests.py b/tests/regressiontests/admin_widgets/tests.py
index 08a1a59766..37fa7bc8ef 100644
--- a/tests/regressiontests/admin_widgets/tests.py
+++ b/tests/regressiontests/admin_widgets/tests.py
@@ -205,6 +205,41 @@ class FilteredSelectMultipleWidgetTest(DjangoTestCase):
             '<select multiple="multiple" name="test" class="selectfilterstacked">\n</select><script type="text/javascript">addEvent(window, "load", function(e) {SelectFilter.init("id_test", "test", 1, "%(ADMIN_MEDIA_PREFIX)s"); });</script>\n' % admin_media_prefix()
         )
 
+class AdminDateWidgetTest(DjangoTestCase):
+    def test_attrs(self):
+        """
+        Ensure that user-supplied attrs are used.
+        Refs #12073.
+        """
+        w = widgets.AdminDateWidget()
+        self.assertEqual(
+            conditional_escape(w.render('test', datetime(2007, 12, 1, 9, 30))),
+            '<input value="2007-12-01" type="text" class="vDateField" name="test" size="10" />',
+        )
+        # pass attrs to widget
+        w = widgets.AdminDateWidget(attrs={'size': 20, 'class': 'myDateField'})
+        self.assertEqual(
+            conditional_escape(w.render('test', datetime(2007, 12, 1, 9, 30))),
+            '<input value="2007-12-01" type="text" class="myDateField" name="test" size="20" />',
+        )
+
+class AdminTimeWidgetTest(DjangoTestCase):
+    def test_attrs(self):
+        """
+        Ensure that user-supplied attrs are used.
+        Refs #12073.
+        """
+        w = widgets.AdminTimeWidget()
+        self.assertEqual(
+            conditional_escape(w.render('test', datetime(2007, 12, 1, 9, 30))),
+            '<input value="09:30:00" type="text" class="vTimeField" name="test" size="8" />',
+        )
+        # pass attrs to widget
+        w = widgets.AdminTimeWidget(attrs={'size': 20, 'class': 'myTimeField'})
+        self.assertEqual(
+            conditional_escape(w.render('test', datetime(2007, 12, 1, 9, 30))),
+            '<input value="09:30:00" type="text" class="myTimeField" name="test" size="20" />',
+        )
 
 class AdminSplitDateTimeWidgetTest(DjangoTestCase):
     def test_render(self):