diff --git a/index.php b/index.php
index 2ddaffc74663ebe711e2740c6bc13e5beb4d9528..baee05066c4f636d2f193b673eba3d781e0f53df 100644
--- a/index.php
+++ b/index.php
@@ -40,7 +40,7 @@ require_once file_exists(PIWIK_INCLUDE_PATH . '/vendor/autoload.php')
     : PIWIK_INCLUDE_PATH . '/../../autoload.php'; // Piwik is installed as a dependency
 
 if(!defined('PIWIK_PRINT_ERROR_BACKTRACE')) {
-    define('PIWIK_PRINT_ERROR_BACKTRACE', true);
+    define('PIWIK_PRINT_ERROR_BACKTRACE', false);
 }
 
 require_once PIWIK_INCLUDE_PATH . '/core/dispatch.php';
\ No newline at end of file
diff --git a/tests/PHPUnit/bootstrap.php b/tests/PHPUnit/bootstrap.php
index 8335346c6b07540f3dcd554e85dfde7e28044e78..01161dfcb7f22c2f6e52f35ade3c4aa5a4072b14 100644
--- a/tests/PHPUnit/bootstrap.php
+++ b/tests/PHPUnit/bootstrap.php
@@ -1,6 +1,6 @@
 <?php
 define('PIWIK_TEST_MODE', true);
-define('PIWIK_PRINT_ERROR_BACKTRACE', false);
+define('PIWIK_PRINT_ERROR_BACKTRACE', true);
 
 if (!defined("PIWIK_PATH_TEST_TO_ROOT")) {
     define('PIWIK_PATH_TEST_TO_ROOT', realpath(dirname(__FILE__) . '/../..'));