diff --git a/include/functions_session.inc.php b/include/functions_session.inc.php
index 747fabfc8..6093abca8 100644
--- a/include/functions_session.inc.php
+++ b/include/functions_session.inc.php
@@ -10,19 +10,47 @@
  * @package functions\session
  */
 
+ // see https://php.watch/versions/8.4/session_set_save_handler-alt-signature-deprecated
+ class PwgSession implements SessionHandlerInterface {
+  public function open(string $path, string $name): bool
+  {
+    return pwg_session_open($path, $name);
+  }
+
+  public function close(): bool
+  {
+    return pwg_session_close();
+  }
+
+  public function read(string $id): string
+  {
+    return pwg_session_read($id);
+  }
+
+  public function write(string $id, string $data): bool
+  {
+    return pwg_session_write($id, $data);
+  }
+
+  public function destroy(string $id): bool
+  {
+    return pwg_session_destroy($id);
+  }
+
+  public function gc(int $max_lifetime): int
+  {
+    return pwg_session_gc();
+  }
+}
 
 if (isset($conf['session_save_handler'])
   and ($conf['session_save_handler'] == 'db')
   and defined('PHPWG_INSTALLED'))
 {
-  session_set_save_handler(
-    'pwg_session_open',
-    'pwg_session_close',
-    'pwg_session_read',
-    'pwg_session_write',
-    'pwg_session_destroy',
-    'pwg_session_gc'
-  );
+  // In PHP 8.4+ calling session_set_save_handler with
+  // two parameters is deprecated. To correct this, 
+  // we pass a SessionHandlerInterface instance.
+  session_set_save_handler(new PwgSession());
 
   if (function_exists('ini_set'))
   {
diff --git a/install.php b/install.php
index 31c92d772..9ec235025 100644
--- a/install.php
+++ b/install.php
@@ -466,13 +466,8 @@ else
   }
   else
   {
-    session_set_save_handler('pwg_session_open',
-      'pwg_session_close',
-      'pwg_session_read',
-      'pwg_session_write',
-      'pwg_session_destroy',
-      'pwg_session_gc'
-    );
+    // See include/functions_session.inc.php
+    session_set_save_handler(new PwgSession());
     if ( function_exists('ini_set') )
     {
       ini_set('session.use_cookies', $conf['session_use_cookies']);