diff --git a/theme/boost/templates/footer.mustache b/theme/boost/templates/footer.mustache
index 80aea254676..9df0e02f3f1 100644
--- a/theme/boost/templates/footer.mustache
+++ b/theme/boost/templates/footer.mustache
@@ -38,7 +38,7 @@
 <footer id="page-footer" class="footer-popover bg-white">
     <div data-region="footer-container-popover">
         {{#output.has_communication_links}}
-            <button onclick="window.open('{{output.communication_url}}', '_blank', 'noreferrer')" class="btn btn-icon bg-primary text-white icon-no-margin btn-footer-communication" aria-label="{{#str}}communicationroomlink, course{{/str}}">
+            <button onclick="window.open('{{output.communication_url}}', '_blank', 'noreferrer')" class="btn btn-icon rounded-circle bg-primary text-white btn-footer-communication" aria-label="{{#str}}communicationroomlink, course{{/str}}">
                 {{#pix}}t/messages-o, core{{/pix}}
             </button>
         {{/output.has_communication_links}}
diff --git a/theme/classic/templates/footer.mustache b/theme/classic/templates/footer.mustache
index c04c52cfcd2..59106bc25db 100644
--- a/theme/classic/templates/footer.mustache
+++ b/theme/classic/templates/footer.mustache
@@ -34,7 +34,7 @@
     <div class="container footer-dark-inner">
         <div id="course-footer">{{{ output.course_footer }}}</div>
         {{#output.has_communication_links}}
-            <button onclick="window.open('{{output.communication_url}}', '_blank', 'noreferrer')" class="btn btn-icon bg-primary text-white icon-no-margin btn-footer-communication" aria-label="{{#str}}communicationroomlink, course{{/str}}">
+            <button onclick="window.open('{{output.communication_url}}', '_blank', 'noreferrer')" class="btn btn-icon rounded-circle bg-primary text-white btn-footer-communication" aria-label="{{#str}}communicationroomlink, course{{/str}}">
                 {{#pix}}t/messages-o, core{{/pix}}
             </button>
         {{/output.has_communication_links}}