diff --git a/theme/boost/templates/columns2.mustache b/theme/boost/templates/columns2.mustache
index dcfe57c3295..51b8d4d25f6 100644
--- a/theme/boost/templates/columns2.mustache
+++ b/theme/boost/templates/columns2.mustache
@@ -82,7 +82,7 @@
                     </div>
                 </section>
                 {{#hasblocks}}
-                <section data-region="blocks-column" class="hidden-print">
+                <section data-region="blocks-column" class="d-print-none">
                     {{{ sidepreblocks }}}
                 </section>
                 {{/hasblocks}}
diff --git a/theme/boost/templates/footer.mustache b/theme/boost/templates/footer.mustache
index d6944d17bc8..4cb4c341485 100644
--- a/theme/boost/templates/footer.mustache
+++ b/theme/boost/templates/footer.mustache
@@ -28,7 +28,7 @@
         {{{ output.login_info }}}
         <div class="tool_usertours-resettourcontainer"></div>
         {{{ output.home_link }}}
-        <nav class="nav navbar-nav hidden-lg-up">
+        <nav class="nav navbar-nav d-md-none">
             {{# output.custom_menu_flat }}
                 <ul class="list-unstyled pt-3">
                     {{> theme_boost/custom_menu_footer }}