diff --git a/README.rst b/README.rst
index 35fd448..ca7d3aa 100644
--- a/README.rst
+++ b/README.rst
@@ -104,12 +104,21 @@ To do so you should override ``JSONFormatter.json_record()``.
 .. code-block:: python
 
     class CustomisedJSONFormatter(json_log_formatter.JSONFormatter):
-        def json_record(self, message, extra, record):
+        def json_record(self, message: str, extra: dict, record: logging.LogRecord) -> dict:
             extra['message'] = message
             extra['user_id'] = current_user_id()
             extra['ip'] = current_ip()
+            
+            # Include builtins
+            extra['level'] = record.levelname
+            extra['name'] = record.name
+            
             if 'time' not in extra:
                 extra['time'] = django.utils.timezone.now()
+            
+            if record.exc_info:
+                extra['exc_info'] = self.formatException(record.exc_info)
+        
             return extra
 
 Let's say you want ``datetime`` to be serialized as timestamp.