diff --git a/kitty/fonts/box_drawing.py b/kitty/fonts/box_drawing.py
index 09d611eb1..f4359ba15 100644
--- a/kitty/fonts/box_drawing.py
+++ b/kitty/fonts/box_drawing.py
@@ -389,6 +389,7 @@ def find_t_for_x(x: int, start_t: float) -> float:
         yield upper, lower
 
 
+@supersampled()
 def D(buf: BufType, width: int, height: int, left: bool = True) -> None:
     c1x = find_bezier_for_D(width, height)
     start = (0, 0)