diff --git a/README.rst b/README.rst
index 77a38f7d..ac081bf9 100644
--- a/README.rst
+++ b/README.rst
@@ -628,7 +628,7 @@ The below python code provides an implementation example:
 
         return m.hexdigest()
 
-The implementation has to sort and encode query string to generate a proper signature.
+The implementation has to sort keys in alphabetical order and encodes query string to generate a proper signature.
 
 The signature is passed to the application by appending the ``sig``
 parameter to the query string; e.g.