diff --git a/theme/boost/scss/moodle/course.scss b/theme/boost/scss/moodle/course.scss
index af8f66f880d..032ff112f2d 100644
--- a/theme/boost/scss/moodle/course.scss
+++ b/theme/boost/scss/moodle/course.scss
@@ -1310,5 +1310,5 @@ span.editinstructions {
 }
 
 #changenumsections {
-    border-top: $border-width solid $activity-item-border;
+    border-top: $border-width solid $primary-light-border;
 }
\ No newline at end of file