diff --git a/src/xml/xpath/concat.js b/src/xml/xpath/concat.js
index 085416b4..53bb90e2 100644
--- a/src/xml/xpath/concat.js
+++ b/src/xml/xpath/concat.js
@@ -1,39 +1,45 @@
 /**
- * @file XML XPath Concat object
+ * @file XML XPath Concat operator
  * @since 1.0.1
  */
 /*#ifndef(UMD)*/
 "use strict";
-/*global _gpfErrorDeclare*/ // Declare new gpf.Error names
-/*global _gpfIgnore*/
 /*global _gpfDefine*/
 /*global _gpfXmlXPathBase*/
-/*exported _gpfXmlXPathConcat*/
+/*exported _gpfXmlXpathConcatNodes*/ // Returns a list of unique nodes
+/*exported _gpfXmlXPathConcat*/ // gpf.xml.xpath.Concat
 /*#endif*/
 
+/**
+ * Concat the node lists to ensure the result contain only unique nodes
+ * @param {gpf.interfaces.IXmlNodeSyncAdapter[]} currentNodes List of nodes to concatenate with
+ * @param {gpf.interfaces.IXmlNodeSyncAdapter[]} newNodes List of nodes to add in the currentNodes list
+ * @return {gpf.interfaces.IXmlNodeSyncAdapter[]} List of unique nodes
+ */
+function _gpfXmlXpathConcatNodes (currentNodes, newNodes) {
+    return currentNodes.concat(newNodes.filter(function (node) {
+        return !curretNodes.includes(node);
+    }));
+}
+
+/**
+ * Implementation of the | operator
+ *
+ * @class gpf.xml.xpath.Concat
+ * @extend gpf.xml.xpath.Base
+ * @since 1.0.1
+ */
 var _gpfXmlXPathConcat = _gpfDefine({
     $class: "gpf.xml.xpath.Concat",
-    $extend: _gpfXmlXPathBase,
-
-    _xpath: [],
+    $extend: _GpfXmlXPathBase,
 
     /**
      * @inheritdoc
      * @since 1.0.1
      */
-    select: function (contextNode, namespaces) {
-        return this._xpath.reduce(function (nodes, xpath) {
-            nodes = nodes.concat(xpath.evaluate(contextNode, namespaces));
+    execute: function (contextNode, namespaces) {
+        return this._children.reduce(function (nodes, xpath) {
+            return _gpfXmlXpathConcatNodes(nodes, xpath.execute(contextNode, namespaces));
         }, []);
-    },
-
-    /**
-     * Implementation of the | operator
-     *
-     * @class gpf.xml.xpath.Concat
-     * @since 1.0.1
-     */
-    constructor: function () {
-        this._xpath = [];
     }
 });