diff --git a/README.md b/README.md
index 6639af0..3ace7cc 100644
--- a/README.md
+++ b/README.md
@@ -112,7 +112,7 @@ def stat(obj_stats):
 
 You define a function with name *stat* and arguments *obj_stats*
 
-*obj_stats* is a python object. You can add new data or manipulate original collected data for your own proposites.
+*obj_stats* is a python object. You can add new data or manipulate original collected data for your own proposites. The function returns *obj_stats* modified.
 
 Next, you need modify your configuration with this line: