diff --git a/classes/Config.php b/classes/Config.php
index 2c2cd4d65..e6e19ba09 100644
--- a/classes/Config.php
+++ b/classes/Config.php
@@ -319,7 +319,7 @@ class Config {
 	 * @return array<string, mixed>|string
 	 */
 	private function _get_version(bool $as_string = true) {
-		$root_dir = dirname(__DIR__);
+		$root_dir = self::get_self_dir();
 
 		if (empty($this->version)) {
 			$this->version["status"] = -1;
@@ -413,7 +413,7 @@ class Config {
 	private function _get_migrations() : Db_Migrations {
 		if (empty($this->migrations)) {
 			$this->migrations = new Db_Migrations();
-			$this->migrations->initialize(dirname(__DIR__) . "/sql", "ttrss_version", true, self::SCHEMA_VERSION);
+			$this->migrations->initialize(self::get_self_dir() . "/sql", "ttrss_version", true, self::SCHEMA_VERSION);
 		}
 
 		return $this->migrations;
@@ -703,4 +703,9 @@ class Config {
 	static function get_user_agent(): string {
 		return sprintf(self::get(self::HTTP_USER_AGENT), self::get_version());
 	}
+
+	static function get_self_dir() : string {
+		return dirname(__DIR__); # we're in classes/Config.php
+	}
+
 }
diff --git a/classes/PluginHost.php b/classes/PluginHost.php
index 7778c008f..700e0e8f5 100644
--- a/classes/PluginHost.php
+++ b/classes/PluginHost.php
@@ -459,10 +459,10 @@ class PluginHost {
 			$span->addEvent("$class_file: load");
 
 			// try system plugin directory first
-			$file = dirname(__DIR__) . "/plugins/$class_file/init.php";
+			$file = Config::get_self_dir() . "/plugins/$class_file/init.php";
 
 			if (!file_exists($file)) {
-				$file = dirname(__DIR__) . "/plugins.local/$class_file/init.php";
+				$file = Config::get_self_dir() . "/plugins.local/$class_file/init.php";
 
 				if (!file_exists($file)) {
 					continue;
diff --git a/classes/Pref_Prefs.php b/classes/Pref_Prefs.php
index da0ee54f7..5aa2382dd 100644
--- a/classes/Pref_Prefs.php
+++ b/classes/Pref_Prefs.php
@@ -1061,7 +1061,7 @@ class Pref_Prefs extends Handler_Protected {
 	 * @return array<int, array{'plugin': string, 'rv': array{'stdout': false|string, 'stderr': false|string, 'git_status': int, 'need_update': bool}|null}>
 	 */
 	static function _get_updated_plugins(): array {
-		$root_dir = dirname(dirname(__DIR__)); # we're in classes/pref/
+		$root_dir = Config::get_self_dir();
 		$plugin_dirs = array_filter(glob("$root_dir/plugins.local/*"), "is_dir");
 		$rv = [];
 
@@ -1185,7 +1185,7 @@ class Pref_Prefs extends Handler_Protected {
 			$plugin_name = basename(clean($_REQUEST['plugin']));
 			$status = 0;
 
-			$plugin_dir = dirname(dirname(__DIR__)) . "/plugins.local/$plugin_name";
+			$plugin_dir = Config::get_self_dir() . "/plugins.local/$plugin_name";
 
 			if (is_dir($plugin_dir)) {
 				$status = $this->_recursive_rmdir($plugin_dir);
@@ -1199,7 +1199,7 @@ class Pref_Prefs extends Handler_Protected {
 		if ($_SESSION["access_level"] >= UserHelper::ACCESS_LEVEL_ADMIN && Config::get(Config::ENABLE_PLUGIN_INSTALLER)) {
 			$plugin_name = basename(clean($_REQUEST['plugin']));
 			$all_plugins = $this->_get_available_plugins();
-			$plugin_dir = dirname(dirname(__DIR__)) . "/plugins.local";
+			$plugin_dir = Config::get_self_dir() . "/plugins.local";
 
 			$work_dir = "$plugin_dir/plugin-installer";
 
@@ -1306,7 +1306,7 @@ class Pref_Prefs extends Handler_Protected {
 	function checkForPluginUpdates(): void {
 		if ($_SESSION["access_level"] >= UserHelper::ACCESS_LEVEL_ADMIN && Config::get(Config::CHECK_FOR_UPDATES) && Config::get(Config::CHECK_FOR_PLUGIN_UPDATES)) {
 			$plugin_name = $_REQUEST["name"] ?? "";
-			$root_dir = dirname(dirname(__DIR__)); # we're in classes/pref/
+			$root_dir = Config::get_self_dir();
 
 			$rv = empty($plugin_name) ? self::_get_updated_plugins() : [
 				["plugin" => $plugin_name, "rv" => self::_plugin_needs_update($root_dir, $plugin_name)],
@@ -1324,8 +1324,7 @@ class Pref_Prefs extends Handler_Protected {
 				$plugins = array_filter($plugins, 'strlen');
 			}
 
-			# we're in classes/pref/
-			$root_dir = dirname(dirname(__DIR__));
+			$root_dir = Config::get_self_dir();
 
 			$rv = [];
 
diff --git a/tests/SelfDirTest.php b/tests/SelfDirTest.php
new file mode 100644
index 000000000..5b7396a66
--- /dev/null
+++ b/tests/SelfDirTest.php
@@ -0,0 +1,12 @@
+<?php
+
+use PHPUnit\Framework\TestCase;
+
+final class ConfigTest extends TestCase {
+	public function test_get_self_dir(): void {
+		$this->assertEquals(
+			dirname(__DIR__), # we're in (app)/tests/
+			Config::get_self_dir()
+		);
+	}
+}