diff --git a/question/preview.php b/question/preview.php
index 52b455a6c93..c01d9b558e3 100644
--- a/question/preview.php
+++ b/question/preview.php
@@ -255,14 +255,14 @@ echo $quba->render_question($slot, $options, $displaynumber);
 // Finish the question form.
 echo html_writer::start_tag('div', array('id' => 'previewcontrols', 'class' => 'controls'));
 echo html_writer::empty_tag('input', $restartdisabled + array('type' => 'submit',
-        'name' => 'restart', 'value' => get_string('restart', 'question'), 'class' => 'btn btn-secondary'));
+        'name' => 'restart', 'value' => get_string('restart', 'question'), 'class' => 'btn btn-secondary mr-1 mb-1'));
 echo html_writer::empty_tag('input', $finishdisabled + array('type' => 'submit',
-        'name' => 'save', 'value' => get_string('save', 'question'), 'class' => 'btn btn-secondary',
+        'name' => 'save', 'value' => get_string('save', 'question'), 'class' => 'btn btn-secondary mr-1 mb-1',
         'id' => 'id_save_question_preview'));
 echo html_writer::empty_tag('input', $filldisabled    + array('type' => 'submit',
-        'name' => 'fill',    'value' => get_string('fillincorrect', 'question'), 'class' => 'btn btn-secondary'));
+        'name' => 'fill',    'value' => get_string('fillincorrect', 'question'), 'class' => 'btn btn-secondary mr-1 mb-1'));
 echo html_writer::empty_tag('input', $finishdisabled + array('type' => 'submit',
-        'name' => 'finish', 'value' => get_string('submitandfinish', 'question'), 'class' => 'btn btn-secondary',
+        'name' => 'finish', 'value' => get_string('submitandfinish', 'question'), 'class' => 'btn btn-secondary mr-1 mb-1',
         'id' => 'id_finish_question_preview'));
 echo html_writer::end_tag('div');
 echo html_writer::end_tag('form');
diff --git a/question/yui/build/moodle-question-preview/moodle-question-preview-debug.js b/question/yui/build/moodle-question-preview/moodle-question-preview-debug.js
index d338ff09477..5902341cd39 100644
--- a/question/yui/build/moodle-question-preview/moodle-question-preview-debug.js
+++ b/question/yui/build/moodle-question-preview/moodle-question-preview-debug.js
@@ -36,7 +36,7 @@ M.question.preview.init = function() {
     M.core_question_engine.init_form(Y, '#responseform');
 
     // Add a close button to the window.
-    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary"/>')
+    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary mb-1"/>')
             .set('value', M.util.get_string('closepreview', 'question'));
 
     closebutton.on('click', function() {
diff --git a/question/yui/build/moodle-question-preview/moodle-question-preview-min.js b/question/yui/build/moodle-question-preview/moodle-question-preview-min.js
index f541e406eac..6e579dee24f 100644
--- a/question/yui/build/moodle-question-preview/moodle-question-preview-min.js
+++ b/question/yui/build/moodle-question-preview/moodle-question-preview-min.js
@@ -1 +1 @@
-YUI.add("moodle-question-preview",function(n,e){M.question=M.question||{},M.question.preview=M.question.preview||{},M.question.preview.init=function(){M.core_question_engine.init_form(n,"#responseform");var e=n.Node.create('<input type="button" class="btn btn-secondary"/>').set("value",M.util.get_string("closepreview","question"));e.on("click",function(){window.close()}),n.one("#previewcontrols").append(e),n.on("submit",M.core_question_engine.prevent_repeat_submission,"#mform1",null,n)}},"@VERSION@",{requires:["base","dom","event-delegate","event-key","core_question_engine"]});
\ No newline at end of file
+YUI.add("moodle-question-preview",function(n,e){M.question=M.question||{},M.question.preview=M.question.preview||{},M.question.preview.init=function(){M.core_question_engine.init_form(n,"#responseform");var e=n.Node.create('<input type="button" class="btn btn-secondary mb-1"/>').set("value",M.util.get_string("closepreview","question"));e.on("click",function(){window.close()}),n.one("#previewcontrols").append(e),n.on("submit",M.core_question_engine.prevent_repeat_submission,"#mform1",null,n)}},"@VERSION@",{requires:["base","dom","event-delegate","event-key","core_question_engine"]});
\ No newline at end of file
diff --git a/question/yui/build/moodle-question-preview/moodle-question-preview.js b/question/yui/build/moodle-question-preview/moodle-question-preview.js
index d338ff09477..5902341cd39 100644
--- a/question/yui/build/moodle-question-preview/moodle-question-preview.js
+++ b/question/yui/build/moodle-question-preview/moodle-question-preview.js
@@ -36,7 +36,7 @@ M.question.preview.init = function() {
     M.core_question_engine.init_form(Y, '#responseform');
 
     // Add a close button to the window.
-    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary"/>')
+    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary mb-1"/>')
             .set('value', M.util.get_string('closepreview', 'question'));
 
     closebutton.on('click', function() {
diff --git a/question/yui/src/preview/js/preview.js b/question/yui/src/preview/js/preview.js
index ebfd0f42c56..a976786638e 100644
--- a/question/yui/src/preview/js/preview.js
+++ b/question/yui/src/preview/js/preview.js
@@ -34,7 +34,7 @@ M.question.preview.init = function() {
     M.core_question_engine.init_form(Y, '#responseform');
 
     // Add a close button to the window.
-    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary"/>')
+    var closebutton = Y.Node.create('<input type="button" class="btn btn-secondary mb-1"/>')
             .set('value', M.util.get_string('closepreview', 'question'));
 
     closebutton.on('click', function() {