diff --git a/classes/config.php b/classes/config.php
index 349706390..b154206da 100644
--- a/classes/config.php
+++ b/classes/config.php
@@ -2,7 +2,9 @@
 class Config {
 	private const _ENVVAR_PREFIX = "TTRSS_";
 
-	/* overriding defaults (defined below in _DEFAULTS[]) via environment: DB_TYPE becomes TTRSS_DB_TYPE, etc */
+	// TODO: this should be extensible so plugins could add their own global directives (with defaults)
+
+	// overriding defaults (defined below in _DEFAULTS[]) via environment: DB_TYPE becomes TTRSS_DB_TYPE, etc
 
 	const DB_TYPE = "DB_TYPE";
 	const DB_HOST = "DB_HOST";
diff --git a/classes/db.php b/classes/db.php
index 5196e7c7d..cbfb9e598 100755
--- a/classes/db.php
+++ b/classes/db.php
@@ -17,8 +17,8 @@ class Db
 	// normal usage is Db::pdo()->prepare(...) etc
 	public function pdo_connect() {
 
-		$db_port = defined('DB_PORT') && DB_PORT ? ';port=' . DB_PORT : '';
-		$db_host = defined('DB_HOST') && DB_HOST ? ';host=' . DB_HOST : '';
+		$db_port = Config::get(Config::DB_PORT) ? ';port=' . Config::get(Config::DB_PORT) : '';
+		$db_host = Config::get(Config::DB_HOST) ? ';host=' . Config::get(Config::DB_HOST) : '';
 
 		try {
 			$pdo = new PDO(Config::get(Config::DB_TYPE) . ':dbname=' . Config::get(Config::DB_NAME) . $db_host . $db_port,
diff --git a/include/functions.php b/include/functions.php
index d42306147..172ba169d 100644
--- a/include/functions.php
+++ b/include/functions.php
@@ -30,7 +30,10 @@
 	ini_set('display_errors', "false");
 	ini_set('display_startup_errors', "false");
 
-	require_once "config.php";
+	// config.php is optional
+	if (stream_resolve_include_path("config.php"))
+		require_once "config.php";
+
 	require_once "autoload.php";
 
 	if (Config::get(Config::DB_TYPE) == "pgsql") {