diff --git a/php/classes/TimeTableMgr.php b/php/classes/TimeTableMgr.php
index 6341288..7c17b92 100644
--- a/php/classes/TimeTableMgr.php
+++ b/php/classes/TimeTableMgr.php
@@ -452,10 +452,11 @@ class TimeTableMgr extends AmdaObjectMgr
 		$attributesToReturn['folderId'] = $folderId;
 
 		if (!$onlyDescription) {
-			$intNodes = $dom->getElementsByTagName('intervals');
+			$xpath = new DOMXPath($dom);
 
-			/** @var DOMElement $intNode */
-			foreach ($intNodes as $intNode) {
+			$intervals = $xpath->query('//intervals');
+
+			foreach ($intervals as $intNode) {
 				$startNodes = $intNode->getElementsByTagName('start');
 				if ($startNodes->length <= 0) {
 					return ['error' => 'Error detected in result file'];
--
libgit2 0.21.2