diff --git a/system/libs/strings.helper.php b/system/libs/strings.helper.php
index 146d76dab..465b2ea4a 100755
--- a/system/libs/strings.helper.php
+++ b/system/libs/strings.helper.php
@@ -134,7 +134,7 @@ function string_explode_list($string_list, $index_as_value = false) {
             if (mb_strpos($row, '|')) {
                 list($index, $value) = explode('|', trim($row));
             } else {
-                $index = string($index_as_value ? $row : ($count + 1));
+                $index = (string)($index_as_value ? $row : ($count + 1));
                 $value = $row;
             }
             $items[trim($index)] = trim($value);