diff --git a/src/Sortable.js b/src/Sortable.js
index 7a8274d21..8df9be449 100644
--- a/src/Sortable.js
+++ b/src/Sortable.js
@@ -5,6 +5,8 @@
  * @license MIT
  */
 
+import './windowCheck.js'; // Always import first
+
 import { version } from '../package.json';
 
 import { IE11OrLess, Edge, FireFox, Safari, IOS, ChromeForAndroid } from './BrowserInfo.js';
@@ -92,10 +94,6 @@ function _dispatchEvent(info) {
 }
 
 
-if (typeof window === "undefined" || !window.document) {
-	throw new Error("Sortable.js requires a window with a document");
-}
-
 let dragEl,
 	parentEl,
 	ghostEl,
diff --git a/src/windowCheck.js b/src/windowCheck.js
new file mode 100644
index 000000000..e6cf9e033
--- /dev/null
+++ b/src/windowCheck.js
@@ -0,0 +1,3 @@
+if (typeof window === "undefined" || !window.document) {
+	throw new Error("Sortable.js requires a window with a document");
+}