diff --git a/theme/canvas/style/core.css b/theme/canvas/style/core.css
index 1ed3270092eba..86b3fe3e94986 100644
--- a/theme/canvas/style/core.css
+++ b/theme/canvas/style/core.css
@@ -520,7 +520,8 @@ body {
     background: #ddd;
 }
 
-table#user-grades tr.avg td.cell {
+table#user-grades tr.avg td.cell,
+table#user-grades tr.avg th.cell {
     background: #eee;
 }