diff --git a/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/DateTimeUpDown/DateTimeUpDown.cs b/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/DateTimeUpDown/DateTimeUpDown.cs
index e33d8c2a..2f7c6e34 100644
--- a/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/DateTimeUpDown/DateTimeUpDown.cs
+++ b/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/DateTimeUpDown/DateTimeUpDown.cs
@@ -134,6 +134,8 @@ namespace Microsoft.Windows.Controls
 
         private void InitializeDateTimeInfoList()
         {
+            _dateTimeInfoList.Clear();
+
             string format = GetFormatString(Format);
             while (format.Length > 0)
             {