diff --git a/README.md b/README.md
index cf612e7..6e78271 100644
--- a/README.md
+++ b/README.md
@@ -13,7 +13,7 @@ Adds drag and drop functionality to SilverStripe 3.0's GridField
 * Upon entering the cms and using GridFieldSortableRows component for the first time you make need to add ?flush=all to the end of the address to force the templates to regenerate
 
 ## Usage
-To enable sorting on a has_many relationship set up an interger field on your data object.
+To enable sorting on a has_many or a many_many relationship set up an interger field on your data object. Also make sure to set the $default_sort on the dataobject to this new interger field to ensure that the sort order is applied when the relationship is requested.
 
 To enable drag and drop sorting on the grid field add the following to your grid field's config
 *Grid Field Config*