diff --git a/src/Perspex.Controls/TextBox.cs b/src/Perspex.Controls/TextBox.cs
index a40f61b026..d44401b1a3 100644
--- a/src/Perspex.Controls/TextBox.cs
+++ b/src/Perspex.Controls/TextBox.cs
@@ -353,6 +353,10 @@ namespace Perspex.Controls
                     }
 
                     break;
+
+                default:
+                    handled = false;
+                    break;
             }
 
             if (movement && ((modifiers & InputModifiers.Shift) != 0))