diff --git a/sources/application/search/criterionconversion/criteriontosearchform.class.inc.php b/sources/application/search/criterionconversion/criteriontosearchform.class.inc.php
index bf67fd1003..82fdb1e5fa 100644
--- a/sources/application/search/criterionconversion/criteriontosearchform.class.inc.php
+++ b/sources/application/search/criterionconversion/criteriontosearchform.class.inc.php
@@ -73,8 +73,11 @@ class CriterionToSearchForm extends CriterionConversionAbstract
 
 		foreach($aAndCriterionRaw as $aCriteria)
 		{
-			$aCriteria['label'] = preg_replace("@^\(@", '', $aCriteria['label']);
-			$aCriteria['label'] = preg_replace("@\)$@", '', $aCriteria['label']);
+			if (isset($aCriteria['label']))
+			{
+				$aCriteria['label'] = preg_replace("@\)$@", '', $aCriteria['label']);
+				$aCriteria['label'] = preg_replace("@^\(@", '', $aCriteria['label']);
+			}
 			$aCriteria['is_removable'] = $bIsRemovable;
 
 			// Check criteria validity