diff --git a/mod/wiki/create_form.php b/mod/wiki/create_form.php
index 3553f45c443..aca70a356d6 100644
--- a/mod/wiki/create_form.php
+++ b/mod/wiki/create_form.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.'/formslib.php');
 
 class mod_wiki_create_form extends moodleform {
diff --git a/mod/wiki/lib.php b/mod/wiki/lib.php
index ddd785c1c19..2e57b618c4b 100644
--- a/mod/wiki/lib.php
+++ b/mod/wiki/lib.php
@@ -34,6 +34,8 @@
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 /**
  * Given an object containing all the necessary data,
  * (defined by the form in mod.html) this function
diff --git a/mod/wiki/locallib.php b/mod/wiki/locallib.php
index 7e8411ae4d0..f7e560364d2 100644
--- a/mod/wiki/locallib.php
+++ b/mod/wiki/locallib.php
@@ -32,6 +32,8 @@
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once($CFG->dirroot . '/mod/wiki/lib.php');
 require_once($CFG->dirroot . '/mod/wiki/parser/parser.php');
 require_once($CFG->libdir . '/filelib.php');
diff --git a/mod/wiki/pagelib.php b/mod/wiki/pagelib.php
index e6a840c099f..34583b2fde1 100644
--- a/mod/wiki/pagelib.php
+++ b/mod/wiki/pagelib.php
@@ -33,6 +33,8 @@
  * @license http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
+defined('MOODLE_INTERNAL') || die();
+
 require_once($CFG->dirroot . '/mod/wiki/edit_form.php');
 require_once($CFG->dirroot . '/tag/lib.php');