diff --git a/wxPython/wxPython/lib/mixins/listctrl.py b/wxPython/wxPython/lib/mixins/listctrl.py
index c422c17cad..029994a8c9 100644
--- a/wxPython/wxPython/lib/mixins/listctrl.py
+++ b/wxPython/wxPython/lib/mixins/listctrl.py
@@ -40,15 +40,18 @@ class wxColumnSorterMixin:
     """
 
     def __init__(self, numColumns):
-        self._colSortFlag = [0] * numColumns
-        self._col = -1
-
+        self.SetColumnCount(numColumns)
         list = self.GetListCtrl()
         if not list:
             raise ValueError, "No wxListCtrl available"
         EVT_LIST_COL_CLICK(list, list.GetId(), self.__OnColClick)
 
 
+    def SetColumnCount(self, newNumColumns):
+        self._colSortFlag = [0] * newNumColumns
+        self._col = -1
+
+
     def SortListItems(self, col=-1, ascending=1):
         """Sort the list on demand.  Can also be used to set the sort column and order."""
         oldCol = self._col