diff --git a/src/App.php b/src/App.php
index 0116083..c46cceb 100644
--- a/src/App.php
+++ b/src/App.php
@@ -52,12 +52,12 @@ class App {
 
     // Define upload_tmp_dir
     if (self::isset('upload_tmp_directory'))
-      ini_set('upload_tmp_dir', self::get('upload_tmp_directory', null, 'string'));
+      Config :: ini_set('upload_tmp_dir', self::get('upload_tmp_directory', null, 'string'));
     if (self::isset('upload_max_filesize')) {
-      ini_set('upload_max_filesize', self::get('upload_max_filesize', null, 'string'));
+      Config :: ini_set('upload_max_filesize', self::get('upload_max_filesize', null, 'string'));
     	// post_max_size must be larger than upload_max_filesize
       // See: https://www.php.net/manual/en/ini.core.php#ini.post-max-size
-      ini_set('post_max_size', strval(self::get('upload_max_filesize', null, 'int') * 1.1));
+      Config :: ini_set('post_max_size', strval(self::get('upload_max_filesize', null, 'int') * 1.1));
     }
 
     if (self :: get('log.enabled', true, 'bool'))
diff --git a/src/Config.php b/src/Config.php
index 94cc442..93d02d5 100644
--- a/src/Config.php
+++ b/src/Config.php
@@ -229,6 +229,17 @@ Class Config {
     return true;
   }
 
+  /**
+   * Helper to set PHP INI option and log error
+   * @param string $option
+   * @param string|int|float|bool|null $value
+   * @return void
+   */
+  public static function ini_set($option, $value) {
+    if (ini_set($option, $value) === false)
+      Log::warning('Fail to set INI options "%s" to "%s"', $option, $value);
+  }
+
 }
 
 # vim: tabstop=4 shiftwidth=4 softtabstop=4 expandtab
diff --git a/src/Session.php b/src/Session.php
index d0e1d3b..22c0df7 100644
--- a/src/Session.php
+++ b/src/Session.php
@@ -35,8 +35,8 @@ class Session {
     if (is_int($max_duration))
       self :: $max_duration = $max_duration;
 
-    ini_set('session.gc_maxlifetime', strval(self :: $max_duration));
-    ini_set('session.cookie_lifetime', strval(self :: $max_duration));
+    Config :: ini_set('session.gc_maxlifetime', strval(self :: $max_duration));
+    Config :: ini_set('session.cookie_lifetime', strval(self :: $max_duration));
 
     // Start session
     session_start();