diff --git a/classes/event/backup_performed.php b/classes/event/backup_performed.php
index 206e730..d9a5502 100644
--- a/classes/event/backup_performed.php
+++ b/classes/event/backup_performed.php
@@ -24,7 +24,7 @@
 
 namespace local_webhooks\event;
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 /**
  * Defines how to work with events.
diff --git a/classes/event/backup_restored.php b/classes/event/backup_restored.php
index f0ba273..0b6b5f9 100644
--- a/classes/event/backup_restored.php
+++ b/classes/event/backup_restored.php
@@ -24,7 +24,7 @@
 
 namespace local_webhooks\event;
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 /**
  * Defines how to work with events.
diff --git a/classes/event/response_answer.php b/classes/event/response_answer.php
index f104eec..aa12845 100644
--- a/classes/event/response_answer.php
+++ b/classes/event/response_answer.php
@@ -24,7 +24,7 @@
 
 namespace local_webhooks\event;
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 /**
  * Defines how to work with events.
diff --git a/classes/event/service_added.php b/classes/event/service_added.php
index 0449e9c..0ec9780 100644
--- a/classes/event/service_added.php
+++ b/classes/event/service_added.php
@@ -24,7 +24,7 @@
 
 namespace local_webhooks\event;
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 /**
  * Defines how to work with events.
diff --git a/classes/event/service_deleted.php b/classes/event/service_deleted.php
index 3937f85..4955e55 100644
--- a/classes/event/service_deleted.php
+++ b/classes/event/service_deleted.php
@@ -24,7 +24,7 @@
 
 namespace local_webhooks\event;
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 /**
  * Defines how to work with events.
diff --git a/classes/event/service_updated.php b/classes/event/service_updated.php
index f6cb3ac..2410d8a 100644
--- a/classes/event/service_updated.php
+++ b/classes/event/service_updated.php
@@ -24,7 +24,7 @@
 
 namespace local_webhooks\event;
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 /**
  * Defines how to work with events.
diff --git a/classes/handler.php b/classes/handler.php
index 8de9b3c..2381173 100644
--- a/classes/handler.php
+++ b/classes/handler.php
@@ -24,7 +24,7 @@
 
 namespace local_webhooks;
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 require_once(__DIR__ . "/../lib.php");
 require_once(__DIR__ . "/../locallib.php");
diff --git a/classes/service_form.php b/classes/service_form.php
index 4f1ce31..3348247 100644
--- a/classes/service_form.php
+++ b/classes/service_form.php
@@ -22,7 +22,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 require_once($CFG->libdir . "/formslib.php");
 
diff --git a/db/events.php b/db/events.php
index a2313c2..f5dd77c 100644
--- a/db/events.php
+++ b/db/events.php
@@ -22,7 +22,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 $observers = array(
     array(
diff --git a/lib.php b/lib.php
index a63d8a4..be88deb 100644
--- a/lib.php
+++ b/lib.php
@@ -22,7 +22,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 require_once(__DIR__ . "/locallib.php");
 
diff --git a/locallib.php b/locallib.php
index 3173a40..ede8e9a 100644
--- a/locallib.php
+++ b/locallib.php
@@ -22,7 +22,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 /**
  * Description of functions of the call of events
diff --git a/settings.php b/settings.php
index 25e5ffd..9a79c13 100644
--- a/settings.php
+++ b/settings.php
@@ -22,7 +22,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 if ($hassiteconfig) {
     $ADMIN->add("server", new admin_externalpage("local_webhooks",
diff --git a/version.php b/version.php
index 7e8cb0b..4e95118 100644
--- a/version.php
+++ b/version.php
@@ -22,7 +22,7 @@
  * @license   http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later
  */
 
-defined("MOODLE_INTERNAL") || die();
+defined('MOODLE_INTERNAL') || die();
 
 $plugin->release   = "3.0.1 (Build: 2018061900)";
 $plugin->version   = 2018061900;