diff --git a/templates/pages/backoffice/ajaxpage/layout.html.twig b/templates/pages/backoffice/ajaxpage/layout.html.twig
index e3a1e3977d..cf85c308a9 100644
--- a/templates/pages/backoffice/ajaxpage/layout.html.twig
+++ b/templates/pages/backoffice/ajaxpage/layout.html.twig
@@ -27,7 +27,7 @@
 			<script type="text/javascript">
 				var aFilesToLoad{{ sId }} = [];
 				{% for sJsFile in aPage.aJsFiles %}
-					if (! $.inArray('{{ sJsFile|raw }}',aListJsFiles))
+                    if ( $.inArray('{{ sJsFile|raw }}',aListJsFiles == -1 ))
 					{
 						aFilesToLoad{{ sId }}.push('{{ sJsFile|raw|add_itop_version }}');
 						aListJsFiles.push("{{ sJsFile|raw }}");