diff --git a/lib/mqa.js b/lib/mqa.js
index 5ca7ad0..e074399 100644
--- a/lib/mqa.js
+++ b/lib/mqa.js
@@ -12,6 +12,7 @@
 	var callbacks = {};
 	var unbindCallbacks = {};
 	var queries = {};
+	var origin = location.origin || location.protocol + "//" + location.hostname + (location.port ? ":" + location.port: "");
 
 	/**
 	 * Helper to convert any array-like object to an actual Array.
@@ -149,8 +150,10 @@
 	mqa.parse = function() {
 		log("Parsing CSS rules");
 		toArray(document.styleSheets).forEach(function(sheet) {
-			if(sheet.cssRules === null) {
-				return; 
+			var isOutsideOfDomain = sheet.href && sheet.href.indexOf("/") !== 0 && sheet.href.indexOf(origin) !== 0;
+			if(isOutsideOfDomain || sheet.cssRules === null) {
+				// ignore sheets out-of-domain or without CSS rules:
+				return;
 			}
 			toArray(sheet.cssRules).forEach(function(rule) {
 				if (rule && rule instanceof CSSMediaRule) {