diff --git a/PySimpleGUI.py b/PySimpleGUI.py
index c9a00233..155e5e1d 100644
--- a/PySimpleGUI.py
+++ b/PySimpleGUI.py
@@ -420,6 +420,7 @@ class Listbox(Element):
         for item in values:
             self.TKListbox.insert(tk.END, item)
         self.TKListbox.selection_set(0, 0)
+        self.Values = values
 
     def SetValue(self, values):
         for index, item in enumerate(self.Values):