diff --git a/theme/boost/scss/moodle/grade.scss b/theme/boost/scss/moodle/grade.scss
index fe40f8b4036..0e2c8ce3a47 100644
--- a/theme/boost/scss/moodle/grade.scss
+++ b/theme/boost/scss/moodle/grade.scss
@@ -447,7 +447,7 @@
 
         tr.heading {
             position: sticky;
-            top: 0vh;
+            top: 0;
             z-index: 1;
         }
 
diff --git a/theme/boost/style/moodle.css b/theme/boost/style/moodle.css
index ee620ba9f27..22a25870e4b 100644
--- a/theme/boost/style/moodle.css
+++ b/theme/boost/style/moodle.css
@@ -19619,7 +19619,7 @@ p.arrow_button {
 
 .path-grade-report-grader .gradeparent tr.heading {
   position: sticky;
-  top: 0vh;
+  top: 0;
   z-index: 1; }
 
 .path-grade-report-grader .gradeparent tr.lastrow {
diff --git a/theme/classic/style/moodle.css b/theme/classic/style/moodle.css
index 594ee07fd7c..1989ebfbd0c 100644
--- a/theme/classic/style/moodle.css
+++ b/theme/classic/style/moodle.css
@@ -19619,7 +19619,7 @@ p.arrow_button {
 
 .path-grade-report-grader .gradeparent tr.heading {
   position: sticky;
-  top: 0vh;
+  top: 0;
   z-index: 1; }
 
 .path-grade-report-grader .gradeparent tr.lastrow {