diff --git a/comment/comment.js b/comment/comment.js
index 13ab753fc10..a736c01847f 100644
--- a/comment/comment.js
+++ b/comment/comment.js
@@ -72,16 +72,14 @@ M.core_comment = {
                 scope.toggle_textarea(false);
             },
             post: function() {
+                var container = Y.one('#comment-list-'+this.client_id);
                 var ta = Y.one('#dlg-content-'+this.client_id);
                 var scope = this;
                 var value = ta.get('value');
                 if (value && value != M.util.get_string('addcomment', 'moodle')) {
                     ta.set('disabled', true);
-                    ta.setStyles({
-                        'backgroundImage': 'url(' + M.util.image_url('i/loading_small', 'core') + ')',
-                        'backgroundRepeat': 'no-repeat',
-                        'backgroundPosition': 'center center'
-                    });
+                    var spinner = M.util.add_spinner(Y, container);
+                    spinner.show();
                     var params = {'content': value};
                     this.request({
                         action: 'add',
@@ -93,7 +91,7 @@ M.core_comment = {
                             var ta = Y.one('#dlg-content-'+cid);
                             ta.set('value', '');
                             ta.set('disabled', false);
-                            ta.setStyle('backgroundImage', 'none');
+                            spinner.remove();
                             scope.toggle_textarea(false);
                             var container = Y.one('#comment-list-'+cid);
                             var result = await scope.render([obj], true);
@@ -401,8 +399,6 @@ M.core_comment = {
                     var collapsedimage = 't/collapsed'; // ltr mode
                     if ( Y.one(document.body).hasClass('dir-rtl') ) {
                         collapsedimage = 't/collapsed_rtl';
-                    } else {
-                        collapsedimage = 't/collapsed';
                     }
                     if (img) {
                         img.set('src', M.util.image_url(collapsedimage, 'core'));
@@ -451,7 +447,8 @@ M.core_comment = {
             },
             wait: function() {
                 var container = Y.one('#comment-list-'+this.client_id);
-                container.set('innerHTML', '<div class="mdl-align"><img src="'+M.util.image_url('i/loading_small', 'core')+'" /></div>');
+                container.set('innerHTML', '');
+                M.util.add_spinner(Y, container).show();
             }
         });
 
diff --git a/comment/lib.php b/comment/lib.php
index 41c77e87147..73994d29d38 100644
--- a/comment/lib.php
+++ b/comment/lib.php
@@ -458,8 +458,6 @@ class comment {
                 $collapsedimage= 't/collapsed';
                 if (right_to_left()) {
                     $collapsedimage= 't/collapsed_rtl';
-                } else {
-                    $collapsedimage= 't/collapsed';
                 }
                 $html .= html_writer::start_tag('a', array(
                     'class' => 'comment-link',
@@ -468,7 +466,8 @@ class comment {
                     'role' => 'button',
                     'aria-expanded' => 'false')
                 );
-                $html .= $OUTPUT->pix_icon($collapsedimage, $this->linktext);
+                $html .= html_writer::img($OUTPUT->image_url($collapsedimage), $this->linktext,
+                    ['id' => 'comment-img-' . $this->cid, 'class' => 'icon']);
                 $html .= html_writer::tag('span', $this->linktext.' '.$countstring, array('id' => 'comment-link-text-'.$this->cid));
                 $html .= html_writer::end_tag('a');
             }
diff --git a/lib/javascript-static.js b/lib/javascript-static.js
index d6b671873f1..40dce9b70d4 100644
--- a/lib/javascript-static.js
+++ b/lib/javascript-static.js
@@ -111,8 +111,6 @@ M.util.CollapsibleRegion = function(Y, id, userpref, strtooltip) {
     var collapsedimage = 't/collapsed'; // ltr mode
     if (right_to_left()) {
         collapsedimage = 't/collapsed_rtl';
-    } else {
-        collapsedimage = 't/collapsed';
     }
     if (this.div.hasClass('collapsed')) {
         // Add the correct image and record the YUI node created in the process