diff --git a/tests/Provider/QueryBuilderProvider.php b/tests/Provider/QueryBuilderProvider.php
index 277067e69..d1a763323 100644
--- a/tests/Provider/QueryBuilderProvider.php
+++ b/tests/Provider/QueryBuilderProvider.php
@@ -1113,6 +1113,7 @@ public static function selectScalar(): array
     {
         return [
             [1, 'SELECT 1'],
+            ['custom_string', 'SELECT "custom_string"'],
             [true, 'SELECT TRUE'],
             [false, 'SELECT FALSE'],
             [12.34, 'SELECT 12.34'],