diff --git a/backup/backup.php b/backup/backup.php
index f85945127ac..3df327aa24a 100644
--- a/backup/backup.php
+++ b/backup/backup.php
@@ -24,6 +24,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+define('NO_OUTPUT_BUFFERING', true);
+
 require_once('../config.php');
 require_once($CFG->dirroot . '/backup/util/includes/backup_includes.php');
 require_once($CFG->dirroot . '/backup/moodle2/backup_plan_builder.class.php');
diff --git a/backup/import.php b/backup/import.php
index 177befc1cfc..57be4943d7a 100644
--- a/backup/import.php
+++ b/backup/import.php
@@ -24,6 +24,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+define('NO_OUTPUT_BUFFERING', true);
+
 // Require both the backup and restore libs
 require_once('../config.php');
 require_once($CFG->dirroot . '/backup/util/includes/backup_includes.php');
diff --git a/backup/restore.php b/backup/restore.php
index 461b7d5cb4b..06f58e65a34 100644
--- a/backup/restore.php
+++ b/backup/restore.php
@@ -23,6 +23,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+define('NO_OUTPUT_BUFFERING', true);
+
 require_once('../config.php');
 require_once($CFG->dirroot . '/backup/util/includes/restore_includes.php');
 
diff --git a/course/publish/backup.php b/course/publish/backup.php
index 63615c13636..ebd5c497caf 100644
--- a/course/publish/backup.php
+++ b/course/publish/backup.php
@@ -30,6 +30,8 @@
  * @copyright  (C) 1999 onwards Martin Dougiamas  http://dougiamas.com
  */
 
+define('NO_OUTPUT_BUFFERING', true);
+
 require_once('../../config.php');
 require_once($CFG->dirroot . '/backup/util/includes/backup_includes.php');
 require_once($CFG->dirroot . '/backup/moodle2/backup_plan_builder.class.php');
diff --git a/grade/report/singleview/index.php b/grade/report/singleview/index.php
index 71f7db4a8d8..a7c66dff9a0 100644
--- a/grade/report/singleview/index.php
+++ b/grade/report/singleview/index.php
@@ -22,6 +22,8 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+define('NO_OUTPUT_BUFFERING', true);
+
 require_once('../../../config.php');
 require_once($CFG->dirroot.'/lib/gradelib.php');
 require_once($CFG->dirroot.'/grade/lib.php');
diff --git a/mod/lesson/view.php b/mod/lesson/view.php
index d74eda30693..97bb040e865 100644
--- a/mod/lesson/view.php
+++ b/mod/lesson/view.php
@@ -23,6 +23,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or late
  **/
 
+define('NO_OUTPUT_BUFFERING', true);
+
 require_once(__DIR__ . '/../../config.php');
 require_once($CFG->dirroot.'/mod/lesson/locallib.php');
 require_once($CFG->libdir . '/grade/constants.php');
diff --git a/mod/quiz/report.php b/mod/quiz/report.php
index d6f05f791b0..5ddc63cd579 100644
--- a/mod/quiz/report.php
+++ b/mod/quiz/report.php
@@ -22,6 +22,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+define('NO_OUTPUT_BUFFERING', true);
 
 require_once(__DIR__ . '/../../config.php');
 require_once($CFG->dirroot . '/mod/quiz/locallib.php');