diff --git a/addons/web_gantt/static/lib/dhtmlxGantt/codebase/dhtmlxcommon.js b/addons/web_gantt/static/lib/dhtmlxGantt/codebase/dhtmlxcommon.js
index 208124b8c74..ab3fe54405b 100644
--- a/addons/web_gantt/static/lib/dhtmlxGantt/codebase/dhtmlxcommon.js
+++ b/addons/web_gantt/static/lib/dhtmlxGantt/codebase/dhtmlxcommon.js
@@ -1,33 +1,3 @@
-dhtmlx=function(obj){
-	for (var a in obj) dhtmlx[a]=obj[a];
-	return dhtmlx; //simple singleton
-};
-dhtmlx.extend_api=function(name,map,ext){
-	var t = window[name];
-	if (!t) return; //component not defined
-	window[name]=function(obj){
-		if (obj && typeof obj == "object" && !obj.tagName){
-			var that = t.apply(this,(map._init?map._init(obj):arguments));
-			//global settings
-			for (var a in dhtmlx)
-				if (map[a]) this[map[a]](dhtmlx[a]);			
-			//local settings
-			for (var a in obj){
-				if (map[a]) this[map[a]](obj[a]);
-				else if (a.indexOf("on")==0){
-					this.attachEvent(a,obj[a]);
-				}
-			}
-		} else
-			var that = t.apply(this,arguments);
-		if (map._patch) map._patch(this);
-		return that||this;
-	};
-	window[name].prototype=t.prototype;
-	if (ext)
-		dhtmlXHeir(window[name].prototype,ext);
-};
-
 dhtmlxAjax={
 	get:function(url,callback){
 		var t=new dtmlXMLLoaderObject(true);
diff --git a/addons/web_gantt/static/lib/dhtmlxGantt/sources/dhtmlxcommon.js b/addons/web_gantt/static/lib/dhtmlxGantt/sources/dhtmlxcommon.js
index 7f68a0a702c..bc7de14346d 100644
--- a/addons/web_gantt/static/lib/dhtmlxGantt/sources/dhtmlxcommon.js
+++ b/addons/web_gantt/static/lib/dhtmlxGantt/sources/dhtmlxcommon.js
@@ -2,37 +2,6 @@
 Copyright DHTMLX LTD. http://www.dhtmlx.com
 To use this component please contact sales@dhtmlx.com to obtain license
 */
-
-dhtmlx=function(obj){
-	for (var a in obj) dhtmlx[a]=obj[a];
-	return dhtmlx; //simple singleton
-};
-dhtmlx.extend_api=function(name,map,ext){
-	var t = window[name];
-	if (!t) return; //component not defined
-	window[name]=function(obj){
-		if (obj && typeof obj == "object" && !obj.tagName){
-			var that = t.apply(this,(map._init?map._init(obj):arguments));
-			//global settings
-			for (var a in dhtmlx)
-				if (map[a]) this[map[a]](dhtmlx[a]);			
-			//local settings
-			for (var a in obj){
-				if (map[a]) this[map[a]](obj[a]);
-				else if (a.indexOf("on")==0){
-					this.attachEvent(a,obj[a]);
-				}
-			}
-		} else
-			var that = t.apply(this,arguments);
-		if (map._patch) map._patch(this);
-		return that||this;
-	};
-	window[name].prototype=t.prototype;
-	if (ext)
-		dhtmlXHeir(window[name].prototype,ext);
-};
-
 dhtmlxAjax={
 	get:function(url,callback){
 		var t=new dtmlXMLLoaderObject(true);