diff --git a/lib/OpenLayers/Format/OWSCommon.js b/lib/OpenLayers/Format/OWSCommon.js
index db975f2be9..2b644d48f3 100644
--- a/lib/OpenLayers/Format/OWSCommon.js
+++ b/lib/OpenLayers/Format/OWSCommon.js
@@ -66,7 +66,7 @@ OpenLayers.Format.OWSCommon = OpenLayers.Class(OpenLayers.Format.XML, {
             // remember version does not correspond to the OWS version
             // it corresponds to the WMS/WFS/WCS etc. request version
             var uri = root.getAttribute("xmlns:ows");
-            if (uri.substring(uri.lastIndexOf("/")+1) === "1.1") {
+            if (uri && uri.substring(uri.lastIndexOf("/")+1) === "1.1") {
                 version ="1.1.0";
             } 
             if(!version) {