Index: wp-admin/includes/user.php
===================================================================
--- wp-admin/includes/user.php	(revision 11898)
+++ wp-admin/includes/user.php	(working copy)
@@ -77,7 +77,10 @@
 
 		// Don't let anyone with 'edit_users' (admins) edit their own role to something without it.
 		if( $user_id != $current_user->id || $wp_roles->role_objects[$_POST['role']]->has_cap( 'edit_users' ))
+		{
 			$user->role = $_POST['role'];
+			do_action('user_role_update', $user_id);
+		}
 
 		// If the new role isn't editable by the logged-in user die with error
 		$editable_roles = get_editable_roles();
Index: wp-admin/users.php
===================================================================
--- wp-admin/users.php	(revision 11898)
+++ wp-admin/users.php	(working copy)
@@ -65,6 +65,7 @@
 
 		$user = new WP_User($id);
 		$user->set_role($_REQUEST['new_role']);
+		do_action('user_role_update', $id);
 	}
 
 	wp_redirect(add_query_arg('update', $update, $redirect));