diff --git a/course/format/singleactivity/lib.php b/course/format/singleactivity/lib.php
index 4c9289b1acf..65cd546dc8f 100644
--- a/course/format/singleactivity/lib.php
+++ b/course/format/singleactivity/lib.php
@@ -338,16 +338,10 @@ class format_singleactivity extends format_base {
      * @return bool|null (null if the check is not possible)
      */
     public function activity_has_subtypes() {
-        global $CFG;
         if (!($modname = $this->get_activitytype())) {
             return null;
         }
-        $libfile = "$CFG->dirroot/mod/$modname/lib.php";
-        if (!file_exists($libfile)) {
-            return null;
-        }
-        include_once($libfile);
-        return function_exists($modname. '_get_types');
+        return component_callback('mod_' . $modname, 'get_types', array(), MOD_SUBTYPE_NO_CHILDREN) !== MOD_SUBTYPE_NO_CHILDREN;
     }
 
     /**
diff --git a/mod/lti/mod_form.php b/mod/lti/mod_form.php
index 3652b475787..1df25e30fa4 100644
--- a/mod/lti/mod_form.php
+++ b/mod/lti/mod_form.php
@@ -75,10 +75,12 @@ class mod_lti_mod_form extends moodleform_mod {
         $mform->setAdvanced('introeditor');
 
         // Display the label to the right of the checkbox so it looks better & matches rest of the form.
-        $coursedesc = $mform->getElement('showdescription');
-        if (!empty($coursedesc)) {
-            $coursedesc->setText(' ' . $coursedesc->getLabel());
-            $coursedesc->setLabel('&nbsp');
+        if ($mform->elementExists('showdescription')) {
+           $coursedesc = $mform->getElement('showdescription');
+           if (!empty($coursedesc)) {
+               $coursedesc->setText(' ' . $coursedesc->getLabel());
+               $coursedesc->setLabel('&nbsp');
+           }
         }
 
         $mform->setAdvanced('showdescription');