diff --git a/Civi/Api4/Service/Schema/SchemaMapBuilder.php b/Civi/Api4/Service/Schema/SchemaMapBuilder.php
index 66efeb3a85e1..74dc0f345369 100644
--- a/Civi/Api4/Service/Schema/SchemaMapBuilder.php
+++ b/Civi/Api4/Service/Schema/SchemaMapBuilder.php
@@ -70,8 +70,8 @@ private function loadTables(SchemaMap $map) {
     /** @var \CRM_Core_DAO $daoName */
     foreach (AllCoreTables::get() as $daoName => $data) {
       $table = new Table($data['table']);
-      foreach ($daoName::fields() as $field => $fieldData) {
-        $this->addJoins($table, $field, $fieldData);
+      foreach ($daoName::fields() as $fieldData) {
+        $this->addJoins($table, $fieldData['name'], $fieldData);
       }
       $map->addTable($table);
       if (in_array($data['name'], $this->apiEntities)) {