diff --git a/selectivizr.js b/selectivizr.js
index 7077c57..5ceaa6c 100755
--- a/selectivizr.js
+++ b/selectivizr.js
@@ -44,7 +44,9 @@ References:
 	// If were not in standards mode, IE is too old / new or we can't create
 	// an XMLHttpRequest object then we should get out now.
 	if (doc.compatMode != 'CSS1Compat' || ieVersion<6 || ieVersion>8 || !xhr) {
-		return;
+	        if(document.documentMode > 8 || typeof document.documentMode === "undefined") {
+	            return;
+	        }
 	}