diff --git a/config/search-string.php b/config/search-string.php
index 1ccc3390a..4d4f4f1be 100644
--- a/config/search-string.php
+++ b/config/search-string.php
@@ -174,7 +174,10 @@ return [
             'document_number' => ['searchable' => true],
             'order_number' => ['searchable' => true],
             'status',
-            'issued_at' => ['date' => true],
+            'issued_at' => [
+                'key' => '/^(invoiced_at|billed_at)$/',
+                'date' => true,
+            ],
             'due_at' => ['date' => true],
             'amount',
             'currency_code' => [