mc:AlternateContent seems to not work

[Mykullski]

Whenever I try to use mc:AlternateContent the formatting seems to be messed up.

Expected Behavior

xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
xmlns:TEST="TEST"        
mc:Ignorable="mc TEST"

<mc:AlternateContent>
   <mc:Choice Requires="TEST">
   </mc:Choice>
   <mc:Fallback>
   </mc:Fallback>
</mc:AlternateContent>

Current Behavior

<AlternateContent xmlns="[mc]http://schemas.openxmlformats.org/markup-compatibility/2006">
   <Choice Requires="TEST">
   </Choice>
   <Fallback>
   </Fallback>
</AlternateContent>

Thanks all, MyKuLLSKI