diff --git a/app/views/exercises/_file_form.html.slim b/app/views/exercises/_file_form.html.slim
index c737f068..5cdfdc98 100644
--- a/app/views/exercises/_file_form.html.slim
+++ b/app/views/exercises/_file_form.html.slim
@@ -4,7 +4,7 @@ li.panel.panel-default
     div.clearfix role="button"
       span = f.object.name
       a.pull-right data-toggle="collapse" data-parent="#files" href="#collapse#{id}" collapse
-  .panel-collapse.collapse.in id="collapse#{id}" role="tabpanel"
+  .panel-collapse.collapse id="collapse#{id}" role="tabpanel"
     .panel-body
       .clearfix = link_to(t('shared.destroy'), '#', class:'btn btn-warning btn-sm discard-file pull-right')
       .form-group
diff --git a/app/views/exercises/show.html.slim b/app/views/exercises/show.html.slim
index fc28272a..ceab96a7 100644
--- a/app/views/exercises/show.html.slim
+++ b/app/views/exercises/show.html.slim
@@ -29,7 +29,7 @@ ul.list-unstyled.panel-group#files
         div.clearfix role="button"
           span.panel-title = file.name_with_extension
           a.pull-right data-toggle="collapse" data-parent="#files" href="#collapse#{file.id}" collapse
-      .panel-collapse.collapse.in id="collapse#{file.id}" role="tabpanel"
+      .panel-collapse.collapse id="collapse#{file.id}" role="tabpanel"
         .panel-body
           - if policy(file).destroy?
             .clearfix = link_to(t('shared.destroy'), file, class:'btn btn-warning btn-sm pull-right', data: {confirm: t('shared.confirm_destroy')}, method: :delete)