diff --git a/main.janet b/main.janet
index f6f02a5..26d1cf8 100644
--- a/main.janet
+++ b/main.janet
@@ -313,7 +313,7 @@
 (defn layout/rows [n x y w h]
   (if (> n 0)
     (do
-      (def height (/ h n))
+      (def height (math/trunc (/ h n)))
       (defn rows [n]
         (if (= n 0) [] (let [Y (- (+ y h) (* n height))]
                          (tuple/join [[x Y w height]]