diff --git a/application/helpers/export_helper.php b/application/helpers/export_helper.php
index f5fb8e77801..e234d8225ef 100644
--- a/application/helpers/export_helper.php
+++ b/application/helpers/export_helper.php
@@ -2633,7 +2633,7 @@ function tsvSurveyExport($surveyid){
  * @param string $column_name
  **/
 function sortArrayByColumn(&$array, $column_name){
-    uasort($array, function($a,$b) {
+    uasort($array, function($a,$b) use ($column_name) {
         return strnatcmp($a["' . $column_name . '"], $b["' . $column_name . '"]);
     });
 }