diff --git a/site_ansto/instrument/util/config_edit.py b/site_ansto/instrument/util/config_edit.py
index 0e4ea080..2a5ac7f9 100755
--- a/site_ansto/instrument/util/config_edit.py
+++ b/site_ansto/instrument/util/config_edit.py
@@ -65,6 +65,13 @@ class RadioButtonListWalker(urwid.SimpleListWalker):
         super(RadioButtonListWalker, self).__init__(mapped_rb_list)
         return 
 
+    def set_modified_callback(self, callback):
+        """This is an abstract method in SimpleListWalker.
+        The urwid doc says use connect_signal(lw, 'modified', callback) instead.
+        """
+        slw = super(RadioButtonListWalker, self)
+        urwid.connect_signal(slw, 'modified', callback)
+        return
 
 class CheckBoxListWalker(urwid.SimpleListWalker):
 
@@ -93,6 +100,14 @@ class CheckBoxListWalker(urwid.SimpleListWalker):
         super(CheckBoxListWalker, self).__init__(mapped_cb_list)
         return
 
+    def set_modified_callback(self, callback):
+        """This is an abstract method in SimpleListWalker.
+        The urwid doc says use connect_signal(lw, 'modified', callback) instead.
+        """
+        slw = super(CheckBoxListWalker, self)
+        urwid.connect_signal(slw, 'modified', callback)
+        return
+
 
 class OptionListWalker(CheckBoxListWalker):