wpf how to prevent double thickness borders at overlap?

wpf how to prevent double thickness borders at overlap?

if you have
<Grid >
<Grid.RowDefinitions>
<RowDefinition Height="*"/>
<RowDefinition Height="2*"/>
<RowDefinition Height="*"/>
</Grid.RowDefinitions>
</Grid
and put a border of thickness 1 into each grid, you will get double
thickness on the border between the grid rows. Is the only way to deal
with this to specify the thickness on each edge of the border or is there
some control that will create borders around the grid for each column
without having double thickness?