diff --git a/include/QueryGenerator/QueryGenerator.php b/include/QueryGenerator/QueryGenerator.php
index 3f452468efa6ad9880c977c59487aa631d10a2ff..148ed5317e8fb185739d412c70303162c65d291c 100644
--- a/include/QueryGenerator/QueryGenerator.php
+++ b/include/QueryGenerator/QueryGenerator.php
@@ -1258,7 +1258,7 @@ class QueryGenerator {
 		if(is_string($value)) {
 			$value = trim($value);
 		} elseif(is_array($value)) {
-			$value = array_map(trim, $value);
+			$value = array_map('trim', $value);
 		}
 		return array('name'=>$fieldname,'value'=>$value,'operator'=>$operator);
 	}