diff --git a/htdocs/core/lib/functions.lib.php b/htdocs/core/lib/functions.lib.php
index ef6e0ddf11c..1acddf54704 100644
--- a/htdocs/core/lib/functions.lib.php
+++ b/htdocs/core/lib/functions.lib.php
@@ -13383,7 +13383,7 @@ function forgeSQLFromUniversalSearchCriteria($filter, &$errorstr = '', $noand =
 
 	// Test the filter syntax
 	$t = preg_replace_callback('/'.$regexstring.'/i', 'dolForgeDummyCriteriaCallback', $filter);
-	$t = str_replace(array('and','or','AND','OR',' '), '', $t);		// Remove the only strings allowed between each () criteria
+	$t = str_ireplace(array('and', 'or', ' '), '', $t);		// Remove the only strings allowed between each () criteria
 	// If the string result contains something else than '()', the syntax was wrong
 
 	if (preg_match('/[^\(\)]/', $t)) {