diff --git a/src/ui/basics.rs b/src/ui/basics.rs
index 5f71d2b..e9b17c6 100644
--- a/src/ui/basics.rs
+++ b/src/ui/basics.rs
@@ -38,8 +38,8 @@ impl CellGrid {
             y,
             width,
             height,
-            num_x,
-            num_y,
+            num_x: if num_y > 0 { num_x } else { 0 }, // if one dimension is 0, both shall be 0
+            num_y: if num_x > 0 { num_y } else { 0 }, // if one dimension is 0, both shall be 0
             pos_x: 0,
             pos_y: 0,
             curr: Cell {x, y, width, height, pos_x: 0, pos_y: 0}