diff --git a/lib/templates/emoji/auto_complete.mustache b/lib/templates/emoji/auto_complete.mustache
index 5063ac2e72a..199abf5576d 100644
--- a/lib/templates/emoji/auto_complete.mustache
+++ b/lib/templates/emoji/auto_complete.mustache
@@ -40,7 +40,7 @@
     {{#emojis}}
         <button
             type="button"
-            class="btn btn-link btn-icon p-0 rounded-lg emoji-button {{#active}}active{{/active}}"
+            class="btn btn-link btn-icon p-0 rounded-3 emoji-button {{#active}}active{{/active}}"
             title="{{displayshortname}}"
             data-region="emoji-button"
             data-unified="{{unified}}"
diff --git a/lib/templates/emoji/emoji_row.mustache b/lib/templates/emoji/emoji_row.mustache
index bbbbb41c2cc..b2b34e76df0 100644
--- a/lib/templates/emoji/emoji_row.mustache
+++ b/lib/templates/emoji/emoji_row.mustache
@@ -41,7 +41,7 @@
         <button
             data-short-names="{{shortnames}}"
             data-unified="{{unified}}"
-            class="btn btn-link btn-icon p-0 rounded-lg emoji-button"
+            class="btn btn-link btn-icon p-0 rounded-3 emoji-button"
             title="{{shortnames}}"
         >{{text}}</button>
     {{/emojis}}
diff --git a/mod/forum/templates/forum_discussion_nested_v2_first_post.mustache b/mod/forum/templates/forum_discussion_nested_v2_first_post.mustache
index 07e92008f15..42ae538b9a6 100644
--- a/mod/forum/templates/forum_discussion_nested_v2_first_post.mustache
+++ b/mod/forum/templates/forum_discussion_nested_v2_first_post.mustache
@@ -154,7 +154,7 @@
                                             {{#pix}} i/moremenu {{/pix}}
                                         </button>
                                         <!-- inline style to fix RTL placement bug -->
-                                        <div class="dropdown-menu dropdown-menu-right rounded-lg shadow border-0" aria-labelledby="post-actions-menu-{{id}}-{{uniqid}}" style="right: auto" role="menubar">
+                                        <div class="dropdown-menu dropdown-menu-right rounded-3 shadow border-0" aria-labelledby="post-actions-menu-{{id}}-{{uniqid}}" style="right: auto" role="menubar">
                                             {{#capabilities}}
                                                 {{#view}}
                                                     <a
diff --git a/theme/boost/scss/moodle/bs5-bridge.scss b/theme/boost/scss/moodle/bs5-bridge.scss
index 6c0eea1abd6..57cebfe152f 100644
--- a/theme/boost/scss/moodle/bs5-bridge.scss
+++ b/theme/boost/scss/moodle/bs5-bridge.scss
@@ -114,3 +114,11 @@ $alert-color-scale: 50% !default;
 .rounded-end {
     @extend .rounded-right;
 }
+
+// Generate sized rounded classes.
+.rounded-1 {
+    @extend .rounded-sm;
+}
+.rounded-3 {
+    @extend .rounded-lg;
+}
diff --git a/theme/boost/style/moodle.css b/theme/boost/style/moodle.css
index 98c0d539cdc..d6b7b28b291 100644
--- a/theme/boost/style/moodle.css
+++ b/theme/boost/style/moodle.css
@@ -19489,7 +19489,7 @@ button.bg-dark:focus {
   border-color: #fff !important;
 }
 
-.rounded-sm {
+.rounded-sm, .rounded-1 {
   border-radius: 0.2rem !important;
 }
 
@@ -19517,7 +19517,7 @@ button.bg-dark:focus {
   border-bottom-left-radius: 0.5rem !important;
 }
 
-.rounded-lg {
+.rounded-lg, .rounded-3 {
   border-radius: 0.6rem !important;
 }
 
diff --git a/theme/classic/style/moodle.css b/theme/classic/style/moodle.css
index 596e7dd6101..924172dada2 100644
--- a/theme/classic/style/moodle.css
+++ b/theme/classic/style/moodle.css
@@ -19489,7 +19489,7 @@ button.bg-dark:focus {
   border-color: #fff !important;
 }
 
-.rounded-sm {
+.rounded-sm, .rounded-1 {
   border-radius: 0.2rem !important;
 }
 
@@ -19517,7 +19517,7 @@ button.bg-dark:focus {
   border-bottom-left-radius: 0.25rem !important;
 }
 
-.rounded-lg {
+.rounded-lg, .rounded-3 {
   border-radius: 0.3rem !important;
 }