diff --git a/django/forms/fields.py b/django/forms/fields.py
index 4cd2911eaad..7f8bac5052e 100644
--- a/django/forms/fields.py
+++ b/django/forms/fields.py
@@ -197,9 +197,11 @@ class CharField(Field):
         return smart_unicode(value)
 
     def widget_attrs(self, widget):
+        attrs = super(CharField, self).widget_attrs(widget)
         if self.max_length is not None and isinstance(widget, (TextInput, PasswordInput)):
             # The HTML attribute is maxlength, not max_length.
-            return {'maxlength': str(self.max_length)}
+            attrs.update({'maxlength': str(self.max_length)})
+        return attrs
 
 class IntegerField(Field):
     default_error_messages = {
diff --git a/tests/regressiontests/forms/tests/fields.py b/tests/regressiontests/forms/tests/fields.py
index 0f9e91a55e4..7dd3a27dc1a 100644
--- a/tests/regressiontests/forms/tests/fields.py
+++ b/tests/regressiontests/forms/tests/fields.py
@@ -136,6 +136,23 @@ class FieldsTests(SimpleTestCase):
         self.assertEqual(f.max_length, None)
         self.assertEqual(f.min_length, 10)
 
+    def test_charfield_widget_attrs(self):
+        """
+        Ensure that CharField.widget_attrs() always returns a dictionary.
+        Refs #15912
+        """
+        # Return an empty dictionary if max_length is None
+        f = CharField()
+        self.assertEqual(f.widget_attrs(TextInput()), {})
+
+        # Or if the widget is not TextInput or PasswordInput
+        f = CharField(max_length=10)
+        self.assertEqual(f.widget_attrs(HiddenInput()), {})
+
+        # Otherwise, return a maxlength attribute equal to max_length
+        self.assertEqual(f.widget_attrs(TextInput()), {'maxlength': '10'})
+        self.assertEqual(f.widget_attrs(PasswordInput()), {'maxlength': '10'})
+
     # IntegerField ################################################################
 
     def test_integerfield_1(self):