Improve the FlowDirection functionality - at the moment setting the flow direction to RightToLeft, partly inverts the Mask value thus messing it up. We are closing this issue as we do not think this is a bug. MaskedInput's Value , Mask and Text properties are not dependent on the FlowDirection property. The issue the bug is originally logged to is easy to reproduce with TextBox only. <TextBox Text="10-Jul-2015" FlowDirection="RightToLeft" /> will produce the string "Jul-2015-10" but not the reversed string of "10-kul-2015". This is how is awpf framework implementation.