diff --git a/src/lib/tick/tick.js b/src/lib/tick/tick.js
index 49715d6..3ca17bc 100644
--- a/src/lib/tick/tick.js
+++ b/src/lib/tick/tick.js
@@ -91,7 +91,7 @@ export function tick(game, containerWidth, containerHeight, deltaTime) {
       ball.x >= paddle.x &&
       ball.x <= paddle.x + paddle.width
     ) {
-      verticalSpeed *= -1;
+      ball.verticalSpeed *= -1;
     }
   } catch (err) {
     console.error(err);