diff --git a/apiclient/discovery.py b/apiclient/discovery.py
index bbd9d68..368ad3e 100644
--- a/apiclient/discovery.py
+++ b/apiclient/discovery.py
@@ -239,6 +239,7 @@
       methodDesc['parameters']['body'] = {
           'description': 'The request body.',
           'type': 'object',
+          'required': True,
           }
 
     argmap = {} # Map from method parameter name to query parameter name