diff --git a/admin/tool/mobile/classes/external.php b/admin/tool/mobile/classes/external.php
index 3c6074005a0..d54d7480b66 100644
--- a/admin/tool/mobile/classes/external.php
+++ b/admin/tool/mobile/classes/external.php
@@ -23,6 +23,7 @@
  */
 
 namespace tool_mobile;
+defined('MOODLE_INTERNAL') || die();
 
 require_once("$CFG->libdir/externallib.php");
 
diff --git a/admin/tool/templatelibrary/classes/external.php b/admin/tool/templatelibrary/classes/external.php
index b92f60859e7..f1c72f55937 100644
--- a/admin/tool/templatelibrary/classes/external.php
+++ b/admin/tool/templatelibrary/classes/external.php
@@ -22,6 +22,7 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 namespace tool_templatelibrary;
+defined('MOODLE_INTERNAL') || die();
 
 require_once("$CFG->libdir/externallib.php");
 
diff --git a/cohort/externallib.php b/cohort/externallib.php
index dcd708f2b22..7595db020f4 100644
--- a/cohort/externallib.php
+++ b/cohort/externallib.php
@@ -23,6 +23,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 
 class core_cohort_external extends external_api {
diff --git a/comment/classes/external.php b/comment/classes/external.php
index beaa75dbec7..6ca460c252d 100644
--- a/comment/classes/external.php
+++ b/comment/classes/external.php
@@ -24,6 +24,8 @@
  * @since      Moodle 2.9
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 require_once("$CFG->dirroot/comment/lib.php");
 
diff --git a/files/externallib.php b/files/externallib.php
index 4e146247148..6f3748cd8d7 100644
--- a/files/externallib.php
+++ b/files/externallib.php
@@ -24,6 +24,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 require_once("$CFG->libdir/filelib.php");
 
diff --git a/group/externallib.php b/group/externallib.php
index c3d25304e1e..53d2dfc61ac 100644
--- a/group/externallib.php
+++ b/group/externallib.php
@@ -24,6 +24,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 
 /**
diff --git a/message/externallib.php b/message/externallib.php
index b0f38eb1217..173b1c420f0 100644
--- a/message/externallib.php
+++ b/message/externallib.php
@@ -24,6 +24,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 require_once($CFG->dirroot . "/message/lib.php");
 
diff --git a/notes/externallib.php b/notes/externallib.php
index 6c07faffeb0..c393fd81b30 100644
--- a/notes/externallib.php
+++ b/notes/externallib.php
@@ -24,6 +24,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 require_once($CFG->dirroot . "/notes/lib.php");
 
diff --git a/question/classes/external.php b/question/classes/external.php
index e11a98a26e1..dae3272acc2 100644
--- a/question/classes/external.php
+++ b/question/classes/external.php
@@ -24,6 +24,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 require_once($CFG->dirroot . '/question/engine/lib.php');
 
diff --git a/tag/classes/external.php b/tag/classes/external.php
index 2fdc6a7a9ca..54fa2045bb3 100644
--- a/tag/classes/external.php
+++ b/tag/classes/external.php
@@ -22,6 +22,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 require_once("$CFG->dirroot/webservice/externallib.php");
 
diff --git a/user/externallib.php b/user/externallib.php
index d8b24a39038..ff0ee8ee75f 100644
--- a/user/externallib.php
+++ b/user/externallib.php
@@ -23,6 +23,8 @@
  * @license    http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once("$CFG->libdir/externallib.php");
 
 /**