diff --git a/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/MaskedTextBox/Implementation/MaskedTextBox.cs b/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/MaskedTextBox/Implementation/MaskedTextBox.cs
index e9be0a53..a2b48351 100644
--- a/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/MaskedTextBox/Implementation/MaskedTextBox.cs
+++ b/ExtendedWPFToolkitSolution/Src/WPFToolkit.Extended/MaskedTextBox/Implementation/MaskedTextBox.cs
@@ -340,7 +340,8 @@ namespace Microsoft.Windows.Controls
             }
 
             //if all text is selected and the user begins to type, we want to delete all selected text and continue typing the new values
-            if (SelectionLength == Text.Length)
+            //but only if the user is not tabbing / shift tabbing
+            if (SelectionLength == Text.Length && (e.Key != Key.Tab && e.Key != Key.LeftShift && e.Key != Key.RightShift))
             {
                 if (provider.RemoveAt(position, endposition))
                     UpdateText(provider, position);