diff --git a/lib/xml2js.js b/lib/xml2js.js
index e953910..672df7c 100644
--- a/lib/xml2js.js
+++ b/lib/xml2js.js
@@ -95,7 +95,7 @@ function onInstruction(instruction) {
     var attributes = {};
     if (instruction.body && (instruction.name.toLowerCase() === 'xml' || options.instructionHasAttributes)) {
         while (instruction.body) {
-            var attribute = instruction.body.match(/([\w:-]+)\s*=\s*"([^"]*)"|'([^']*)'|(\w+)\s*/);
+            var attribute = instruction.body.match(/([\w:-]+)\s*=\s*(?:"([^"]*)"|'([^']*)'|(\w+))\s*/);
             if (!attribute) {
                 break;
             }
diff --git a/package.json b/package.json
index c7b58c7..25f6f5c 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "xml-js",
-  "version": "1.3.3",
+  "version": "1.3.4",
   "description": "A convertor between XML text and Javascript object / JSON text.",
   "repository": {
     "type": "git",