diff --git a/theme/boost/scss/moodle/admin.scss b/theme/boost/scss/moodle/admin.scss
index 6c567f44204..f427252cce9 100644
--- a/theme/boost/scss/moodle/admin.scss
+++ b/theme/boost/scss/moodle/admin.scss
@@ -247,7 +247,8 @@
     margin: 0;
 }
 
-.path-admin {
+.path-admin,
+.format-site {
     .header-maxwidth,
     .secondary-navigation {
         max-width: none;
diff --git a/theme/boost/style/moodle.css b/theme/boost/style/moodle.css
index ef6481cb90c..3d00276f2da 100644
--- a/theme/boost/style/moodle.css
+++ b/theme/boost/style/moodle.css
@@ -12592,7 +12592,9 @@ body.dragging .dragging {
   margin: 0; }
 
 .path-admin .header-maxwidth,
-.path-admin .secondary-navigation {
+.path-admin .secondary-navigation,
+.format-site .header-maxwidth,
+.format-site .secondary-navigation {
   max-width: none; }
 
 .plugincheckwrapper {
diff --git a/theme/classic/style/moodle.css b/theme/classic/style/moodle.css
index 8d37aa5d514..a6b873bdc03 100644
--- a/theme/classic/style/moodle.css
+++ b/theme/classic/style/moodle.css
@@ -12592,7 +12592,9 @@ body.dragging .dragging {
   margin: 0; }
 
 .path-admin .header-maxwidth,
-.path-admin .secondary-navigation {
+.path-admin .secondary-navigation,
+.format-site .header-maxwidth,
+.format-site .secondary-navigation {
   max-width: none; }
 
 .plugincheckwrapper {