diff --git a/django/forms/boundfield.py b/django/forms/boundfield.py
index 4867e72deb..df3de5848e 100644
--- a/django/forms/boundfield.py
+++ b/django/forms/boundfield.py
@@ -51,6 +51,7 @@ class BoundField(object):
         """
         id_ = self.field.widget.attrs.get('id') or self.auto_id
         attrs = {'id': id_} if id_ else {}
+        attrs = self.build_widget_attrs(attrs)
         for subwidget in self.field.widget.subwidgets(self.html_name, self.value(), attrs):
             yield subwidget
 
@@ -85,10 +86,7 @@ class BoundField(object):
             widget.is_localized = True
 
         attrs = attrs or {}
-        if not widget.is_hidden and self.field.required and self.form.use_required_attribute:
-            attrs['required'] = True
-        if self.field.disabled:
-            attrs['disabled'] = True
+        attrs = self.build_widget_attrs(attrs, widget)
         auto_id = self.auto_id
         if auto_id and 'id' not in attrs and 'id' not in widget.attrs:
             if not only_initial:
@@ -227,3 +225,13 @@ class BoundField(object):
         widget = self.field.widget
         id_ = widget.attrs.get('id') or self.auto_id
         return widget.id_for_label(id_)
+
+    def build_widget_attrs(self, attrs, widget=None):
+        if not widget:
+            widget = self.field.widget
+        attrs = dict(attrs)  # Copy attrs to avoid modifying the argument.
+        if not widget.is_hidden and self.field.required and self.form.use_required_attribute:
+            attrs['required'] = True
+        if self.field.disabled:
+            attrs['disabled'] = True
+        return attrs
diff --git a/django/forms/widgets.py b/django/forms/widgets.py
index 604a6a401a..217f37b022 100644
--- a/django/forms/widgets.py
+++ b/django/forms/widgets.py
@@ -787,6 +787,13 @@ class CheckboxSelectMultiple(RendererMixin, SelectMultiple):
     renderer = CheckboxFieldRenderer
     _empty_value = []
 
+    def build_attrs(self, extra_attrs=None, **kwargs):
+        attrs = super(CheckboxSelectMultiple, self).build_attrs(extra_attrs, **kwargs)
+        # Remove the 'required' attribute because browser validation would
+        # require all checkboxes to be checked instead of at least one.
+        attrs.pop('required', None)
+        return attrs
+
 
 class MultiWidget(Widget):
     """
diff --git a/docs/ref/forms/widgets.txt b/docs/ref/forms/widgets.txt
index 6a8cdf3c70..aae92a37c9 100644
--- a/docs/ref/forms/widgets.txt
+++ b/docs/ref/forms/widgets.txt
@@ -714,8 +714,10 @@ Selector and checkbox widgets
     The outer ``<ul>`` container receives the ``id`` attribute of the widget,
     if defined, or :attr:`BoundField.auto_id` otherwise.
 
-Like :class:`RadioSelect`, you can now loop over the individual checkboxes making
-up the lists. See the documentation of :class:`RadioSelect` for more details.
+Like :class:`RadioSelect`, you can loop over the individual checkboxes for the
+widget's choices. Unlike :class:`RadioSelect`, the checkboxes won't include the
+``required`` HTML attribute if the field is required because browser validation
+would require all checkboxes to be checked instead of at least one.
 
 When looping over the checkboxes, the ``label`` and ``input`` tags include
 ``for`` and ``id`` attributes, respectively. Each checkbox has an
diff --git a/tests/forms_tests/tests/test_forms.py b/tests/forms_tests/tests/test_forms.py
index 2bd49b7361..a9c3c74b69 100644
--- a/tests/forms_tests/tests/test_forms.py
+++ b/tests/forms_tests/tests/test_forms.py
@@ -646,9 +646,9 @@ Java</label></li>
         self.assertHTMLEqual(
             t.render(Context({'form': f})),
             """<div class="myradio"><label for="id_language_0">
-<input id="id_language_0" name="language" type="radio" value="P" /> Python</label></div>
+<input id="id_language_0" name="language" type="radio" value="P" required /> Python</label></div>
 <div class="myradio"><label for="id_language_1">
-<input id="id_language_1" name="language" type="radio" value="J" /> Java</label></div>"""
+<input id="id_language_1" name="language" type="radio" value="J" required /> Java</label></div>"""
         )
 
     def test_form_with_iterable_boundfield(self):
@@ -661,17 +661,17 @@ Java</label></li>
         f = BeatleForm(auto_id=False)
         self.assertHTMLEqual(
             '\n'.join(str(bf) for bf in f['name']),
-            """<label><input type="radio" name="name" value="john" /> John</label>
-<label><input type="radio" name="name" value="paul" /> Paul</label>
-<label><input type="radio" name="name" value="george" /> George</label>
-<label><input type="radio" name="name" value="ringo" /> Ringo</label>"""
+            """<label><input type="radio" name="name" value="john" required /> John</label>
+<label><input type="radio" name="name" value="paul" required /> Paul</label>
+<label><input type="radio" name="name" value="george" required /> George</label>
+<label><input type="radio" name="name" value="ringo" required /> Ringo</label>"""
         )
         self.assertHTMLEqual(
             '\n'.join('<div>%s</div>' % bf for bf in f['name']),
-            """<div><label><input type="radio" name="name" value="john" /> John</label></div>
-<div><label><input type="radio" name="name" value="paul" /> Paul</label></div>
-<div><label><input type="radio" name="name" value="george" /> George</label></div>
-<div><label><input type="radio" name="name" value="ringo" /> Ringo</label></div>"""
+            """<div><label><input type="radio" name="name" value="john" required /> John</label></div>
+<div><label><input type="radio" name="name" value="paul" required /> Paul</label></div>
+<div><label><input type="radio" name="name" value="george" required /> George</label></div>
+<div><label><input type="radio" name="name" value="ringo" required /> Ringo</label></div>"""
         )
 
     def test_form_with_noniterable_boundfield(self):
@@ -680,7 +680,7 @@ Java</label></li>
             name = CharField()
 
         f = BeatleForm(auto_id=False)
-        self.assertHTMLEqual('\n'.join(str(bf) for bf in f['name']), '<input type="text" name="name" />')
+        self.assertHTMLEqual('\n'.join(str(bf) for bf in f['name']), '<input type="text" name="name" required />')
 
     def test_boundfield_slice(self):
         class BeatleForm(Form):
@@ -803,18 +803,18 @@ Java</label></li>
 
         f = SongForm(auto_id=False)
         self.assertHTMLEqual(str(f['composers']), """<ul>
-<li><label><input type="checkbox" name="composers" value="J" required /> John Lennon</label></li>
-<li><label><input type="checkbox" name="composers" value="P" required /> Paul McCartney</label></li>
+<li><label><input type="checkbox" name="composers" value="J" /> John Lennon</label></li>
+<li><label><input type="checkbox" name="composers" value="P" /> Paul McCartney</label></li>
 </ul>""")
         f = SongForm({'composers': ['J']}, auto_id=False)
         self.assertHTMLEqual(str(f['composers']), """<ul>
-<li><label><input checked="checked" type="checkbox" name="composers" value="J" required /> John Lennon</label></li>
-<li><label><input type="checkbox" name="composers" value="P" required /> Paul McCartney</label></li>
+<li><label><input checked="checked" type="checkbox" name="composers" value="J" /> John Lennon</label></li>
+<li><label><input type="checkbox" name="composers" value="P" /> Paul McCartney</label></li>
 </ul>""")
         f = SongForm({'composers': ['J', 'P']}, auto_id=False)
         self.assertHTMLEqual(str(f['composers']), """<ul>
-<li><label><input checked="checked" type="checkbox" name="composers" value="J" required /> John Lennon</label></li>
-<li><label><input checked="checked" type="checkbox" name="composers" value="P" required /> Paul McCartney</label></li>
+<li><label><input checked="checked" type="checkbox" name="composers" value="J" /> John Lennon</label></li>
+<li><label><input checked="checked" type="checkbox" name="composers" value="P" /> Paul McCartney</label></li>
 </ul>""")
         # Test iterating on individual checkboxes in a template
         t = Template('{% for checkbox in form.composers %}<div class="mycheckbox">{{ checkbox }}</div>{% endfor %}')
@@ -839,9 +839,9 @@ Java</label></li>
             str(f['composers']),
             """<ul id="composers_id">
 <li><label for="composers_id_0">
-<input type="checkbox" name="composers" value="J" id="composers_id_0" required /> John Lennon</label></li>
+<input type="checkbox" name="composers" value="J" id="composers_id_0" /> John Lennon</label></li>
 <li><label for="composers_id_1">
-<input type="checkbox" name="composers" value="P" id="composers_id_1" required /> Paul McCartney</label></li>
+<input type="checkbox" name="composers" value="P" id="composers_id_1" /> Paul McCartney</label></li>
 </ul>"""
         )