diff --git a/src/Dibi/Drivers/PostgreResult.php b/src/Dibi/Drivers/PostgreResult.php
index d2e9cf49..88af04e9 100644
--- a/src/Dibi/Drivers/PostgreResult.php
+++ b/src/Dibi/Drivers/PostgreResult.php
@@ -21,7 +21,7 @@ use function is_resource;
 class PostgreResult implements Dibi\ResultDriver
 {
 	public function __construct(
-		private PgSql\Result $resultSet,
+		private readonly PgSql\Result $resultSet,
 	) {
 	}