diff --git a/mod/assign/gradingtable.php b/mod/assign/gradingtable.php
index c77a8f9bee5..93c801cc3b5 100644
--- a/mod/assign/gradingtable.php
+++ b/mod/assign/gradingtable.php
@@ -302,6 +302,10 @@ class assign_grading_table extends table_sql implements renderable {
             }
         }
 
+        // When there is no data we still want the column headers printed in the csv file.
+        if ($this->is_downloading()) {
+            $this->start_output();
+        }
     }
 
     /**