diff --git a/js/worker-main.js b/js/worker-main.js
index e77cb04..28c90a8 100644
--- a/js/worker-main.js
+++ b/js/worker-main.js
@@ -43,7 +43,7 @@
     var direction = 39; // right
     
     square.style.top = 0;
-    square.style.left = 20;
+    square.style.left = '20px';
     square.style.height = SQUARE_SIZE;
     square.style.width = SQUARE_SIZE;
     
@@ -89,4 +89,4 @@
     // start the square animating
     requestAnimationFrame(moveSquare);
     
-}());
\ No newline at end of file
+}());