diff --git a/renderer.php b/renderer.php
index 00036de..de86e03 100644
--- a/renderer.php
+++ b/renderer.php
@@ -2198,7 +2198,7 @@ class mod_attendance_renderer extends plugin_renderer_base {
 
         $row = new html_table_row();
         $text = ($reportdata->pageparams->view == ATT_VIEW_SUMMARY) ? '' : get_string('summary');
-        $cell = $this->build_data_cell($text, false, true, $usercolspan);
+        $cell = $this->build_data_cell($text, false, true);
         $cell->attributes['class'] = $cell->attributes['class'] . ' headcol';
         $row->cells[] = $cell;
         if (!empty($usercolspan)) {
diff --git a/styles.css b/styles.css
index e635046..22a3271 100644
--- a/styles.css
+++ b/styles.css
@@ -281,14 +281,14 @@
     overflow-x: scroll;
     overflow-y: visible;
     padding: 0;
-    margin-left: 180px;
 }
 
 #page-mod-attendance-report .attendancereporttable .headcol {
-    position: absolute;
+    position: sticky;
     width: 200px;
     left: 0;
-    top: auto;
+    vertical-align: top;
+    background: white;
     border-top-width: 1px;
 }