diff --git a/app/DAL/Studies/WorklistBase.php b/app/DAL/Studies/WorklistBase.php
index e201672..d5b6873 100644
--- a/app/DAL/Studies/WorklistBase.php
+++ b/app/DAL/Studies/WorklistBase.php
@@ -115,9 +115,9 @@ public function setSortOrder(string $order): self
         $this->sortColumns = [];
         if (filled($order)) {
             $orders = explode(',', $order);
-            foreach ($orders as $order) {
-                $column = ltrim($order, '-');
-                $dir = ($order[0] == '-') ? 'desc' : 'asc';
+            foreach ($orders as $sort) {
+                $column = ltrim($sort, '-');
+                $dir = ($sort[0] === '-') ? 'desc' : 'asc';
                 $this->sortColumns[] = [$column => $dir];
             }
         }