diff --git a/kitty/fonts/box_drawing.py b/kitty/fonts/box_drawing.py
index 2ba7f5719..2bd3bce88 100644
--- a/kitty/fonts/box_drawing.py
+++ b/kitty/fonts/box_drawing.py
@@ -479,11 +479,11 @@ def rectircle_equations(
     if left_quadrants:
         def x(t: float) -> float:
             xterm = 1 - pow(t, yexp)
-            return cell_width - abs(a * pow(xterm, xexp)) - adjust_x
+            return math.floor(cell_width - abs(a * pow(xterm, xexp)) - adjust_x)
     else:
         def x(t: float) -> float:
             xterm = 1 - pow(t, yexp)
-            return abs(a * pow(xterm, xexp))
+            return math.ceil(abs(a * pow(xterm, xexp)))
 
     return x, y