diff --git a/lib/browser.js b/lib/browser.js
index 51d19792..e536702e 100644
--- a/lib/browser.js
+++ b/lib/browser.js
@@ -1,10 +1,13 @@
-var _global = (function () {
-	if (!this && typeof global !== 'undefined') {
-		return global;
-	}
-	return this;
-})();
-var NativeWebSocket = _global.WebSocket || _global.MozWebSocket;
+var _globalThis;
+try {
+	_globalThis = require('es5-ext/global');
+} catch (error) {
+} finally {
+	if (!_globalThis && typeof window !== 'undefined') { _globalThis = window; }
+	if (!_globalThis) { throw new Error('Could not determine global this'); }
+}
+
+var NativeWebSocket = _globalThis.WebSocket || _globalThis.MozWebSocket;
 var websocket_version = require('./version');
 
 
diff --git a/package.json b/package.json
index 7aeb5cec..4cbff181 100644
--- a/package.json
+++ b/package.json
@@ -28,6 +28,7 @@
   },
   "dependencies": {
     "debug": "^2.2.0",
+    "es5-ext": "^0.10.50",
     "nan": "^2.14.0",
     "typedarray-to-buffer": "^3.1.5",
     "yaeti": "^0.0.6"