diff --git a/app/views/similar_terms/_form.html.erb b/app/views/similar_terms/_form.html.erb
index d449543..62a7fd0 100644
--- a/app/views/similar_terms/_form.html.erb
+++ b/app/views/similar_terms/_form.html.erb
@@ -6,6 +6,7 @@
     <div class="col">
       <%= f.text_field :terms, hide_label: true, autofocus: (@terms ? false : true), wrapper_class: 'mb-0',
                        class: 'form-control-lg form-control-borderless border-0', autocomplete: 'off',
+                       required: true,
                        value: (@terms ? InlineDataHelper.generate_inline_values(@terms) : params[:terms])
       %>
     </div>