diff --git a/bootstrap.php b/bootstrap.php
index cbe05b7a..9fdf627f 100644
--- a/bootstrap.php
+++ b/bootstrap.php
@@ -4,6 +4,7 @@ namespace JKingWeb\Arsse;
 
 const BASE = __DIR__.DIRECTORY_SEPARATOR;
 const NS_BASE = __NAMESPACE__."\\";
+const VERSION = "0.0.0";
 
 if(!defined(NS_BASE."INSTALL")) define(NS_BASE."INSTALL", false);
 
diff --git a/lib/Conf.php b/lib/Conf.php
index 352cc42c..5decf1d7 100644
--- a/lib/Conf.php
+++ b/lib/Conf.php
@@ -29,9 +29,16 @@ class Conf {
     public $userComposeNames        = true;
     public $userTempPasswordLength  = 20;
 
-    public $userAgentString         = 'Arsse (https://code.jkingweb.ca/jking/arsse)';
+    public $userAgentString;
 
     public function __construct(string $import_file = "") {
+        $this->userAgentString = sprintf('Arsse/%s (%s %s; %s; https://code.jkingweb.ca/jking/arsse) PicoFeed (https://github.com/fguillot/picoFeed)',
+            VERSION, // Arsse version
+            php_uname('s'), // OS
+            php_uname('r'), // OS version
+            php_uname('m') // platform architecture
+        );
+
         if($import_file != "") $this->importFile($import_file);
     }