diff --git a/main/exercise/question_admin.inc.php b/main/exercise/question_admin.inc.php
index c80526af99..bc72f11eee 100755
--- a/main/exercise/question_admin.inc.php
+++ b/main/exercise/question_admin.inc.php
@@ -23,11 +23,11 @@ if (is_object($objQuestion)) {
     // FORM CREATION
     $form = new FormValidator('question_admin_form', 'post', $action);
     if (isset($_GET['editQuestion'])) {
-        $class = "btn btn-default";
+        $class = 'btn btn-default';
         $text = get_lang('ModifyQuestion');
         $type = isset($_GET['type']) ? Security::remove_XSS($_GET['type']) : null;
     } else {
-        $class = "btn btn-default";
+        $class = 'btn btn-default';
         $text = get_lang('AddQuestionToExercise');
         $type = $_REQUEST['answerType'];
     }
diff --git a/main/inc/lib/template.lib.php b/main/inc/lib/template.lib.php
index 8cd322d5e9..f61358e110 100755
--- a/main/inc/lib/template.lib.php
+++ b/main/inc/lib/template.lib.php
@@ -774,7 +774,7 @@ class Template
             $bowerJsFiles[] = 'ckeditor/ckeditor.js';
         }
 
-        if (api_get_setting('include_asciimathml_script') == 'true') {
+        if (api_get_setting('include_asciimathml_script') === 'true') {
             $bowerJsFiles[] = 'MathJax/MathJax.js?config=TeX-MML-AM_HTMLorMML';
         }