diff --git a/apiclient/discovery.py b/apiclient/discovery.py
index 1bac08c..d15c5b2 100644
--- a/apiclient/discovery.py
+++ b/apiclient/discovery.py
@@ -68,7 +68,7 @@
       headers['user-agent'] += ' '
     else:
       headers['user-agent'] = ''
-    headers['user-agent'] += 'google-api-client-python/1.0'
+    headers['user-agent'] += 'google-api-python-client/1.0'
     if body_value is None:
       return (headers, path_params, query, None)
     else: