diff --git a/README.md b/README.md
index fec0ae1..1ecc810 100644
--- a/README.md
+++ b/README.md
@@ -4,4 +4,5 @@
 
 1. Fork it
 1. Change anything you want (add commits using ```git``` or simply change files using Github web interface)
-1. Create new Pull Request
+1. If you have Python and PyYAML installed, you can run ```checker.py``` to verify that your translation file contains correct set of keys
+1. Create a new Pull Request
diff --git a/checker.py b/checker.py
index ce6c33c..aca737e 100755
--- a/checker.py
+++ b/checker.py
@@ -3,6 +3,15 @@
 import yaml
 import sets
 
+"""
+Check that all translation have proper keys
+
+This script can be used to check that all translations have the same set
+of keys as the 'master' locale - English in our case.
+
+Just run the script. No output is good.
+"""
+
 master = "en"
 
 def compare_dicts(master, victim, path):