diff --git a/oauth2client/client.py b/oauth2client/client.py
index 373ccbb..de15e09 100644
--- a/oauth2client/client.py
+++ b/oauth2client/client.py
@@ -1864,7 +1864,7 @@ class OAuth2WebServerFlow(Flow):
       logger.info('Failed to retrieve access token: %s', content)
       if 'error' in d:
         # you never know what those providers got to say
-        error_msg = str(d['error'])
+        error_msg = str(d['error']) + str(d.get('error_description', ''))
       else:
         error_msg = 'Invalid response: %s.' % str(resp.status)
       raise FlowExchangeError(error_msg)