1 files changed, 3 insertions, 1 deletions

diff --git a/index.php b/index.php
index 0369da7a7f..d464377c56 100644
--- a/index.php
+++ b/index.php
@@ -40,7 +40,9 @@ require_once PIWIK_INCLUDE_PATH . '/vendor/autoload.php';
 require_once PIWIK_INCLUDE_PATH . '/core/Loader.php';
 require_once PIWIK_INCLUDE_PATH . '/core/functions.php';
 
-define('PIWIK_PRINT_ERROR_BACKTRACE', false);
+if(!defined('PIWIK_PRINT_ERROR_BACKTRACE')) {
+    define('PIWIK_PRINT_ERROR_BACKTRACE', false);
+}
 
 if (!defined('PIWIK_ENABLE_ERROR_HANDLER') || PIWIK_ENABLE_ERROR_HANDLER) {
     require_once PIWIK_INCLUDE_PATH . '/core/Error.php';