diff --git a/composer.json b/composer.json
index 1ff6b168bed2..f8aa3f13bd64 100644
--- a/composer.json
+++ b/composer.json
@@ -29,7 +29,7 @@
         "phpunit/phpcov": "^9.0.2 || ^10.0",
         "phpunit/phpunit": "^10.5.16 || ^11.2",
         "predis/predis": "^3.0",
-        "rector/rector": "2.8.3",
+        "rector/rector": "2.8.4",
         "shipmonk/phpstan-baseline-per-identifier": "^2.0"
     },
     "replace": {
diff --git a/system/Database/OCI8/Result.php b/system/Database/OCI8/Result.php
index 6882bff00f45..290e68673b64 100644
--- a/system/Database/OCI8/Result.php
+++ b/system/Database/OCI8/Result.php
@@ -36,7 +36,7 @@ public function getFieldNames(): array
 
     public function getFieldData(): array
     {
-        return array_map(fn ($fieldIndex) => (object) [
+        return array_map(fn ($fieldIndex): stdClass => (object) [
             'name'       => oci_field_name($this->resultID, $fieldIndex),
             'type'       => oci_field_type($this->resultID, $fieldIndex),
             'max_length' => oci_field_size($this->resultID, $fieldIndex),