Fix for 1, 0 being rendered as true, false in the admin. Closes #3227.

rest_framework/templatetags/rest_framework.py

@@ -111,7 +111,7 @@ def add_class(value, css_class):
 def format_value(value):
     if getattr(value, 'is_hyperlink', False):
         return mark_safe('<a href=%s>%s</a>' % (value, escape(value.name)))
-    if value in (True, False, None):
+    if value is None or isinstance(value, bool):
         return mark_safe('<code>%s</code>' % {True: 'true', False: 'false', None: 'null'}[value])
     elif isinstance(value, list):
         if any([isinstance(item, (list, dict)) for item in value]):