diff --git a/modules/hero.js b/modules/hero.js
index 3415db8..0d881d8 100644
--- a/modules/hero.js
+++ b/modules/hero.js
@@ -1,4 +1,4 @@
-var raf = (window && window.requestAnimationFrame) || setTimeout;
+var raf = (typeof window !== `undefined` && window.requestAnimationFrame) || setTimeout;
 var nextFrame = function(fn) { raf(function() { raf(fn); }); };
 
 function setNextFrame(obj, prop, val) {
diff --git a/modules/style.js b/modules/style.js
index 07b6a74..31ae880 100644
--- a/modules/style.js
+++ b/modules/style.js
@@ -1,4 +1,4 @@
-var raf = (window && window.requestAnimationFrame) || setTimeout;
+var raf = (typeof window !== `undefined` && window.requestAnimationFrame) || setTimeout;
 var nextFrame = function(fn) { raf(function() { raf(fn); }); };
 
 function setNextFrame(obj, prop, val) {