diff --git a/lib/excellib.class.php b/lib/excellib.class.php
index 43ce6d9855a..2bd4a0f8eed 100644
--- a/lib/excellib.class.php
+++ b/lib/excellib.class.php
@@ -489,7 +489,7 @@ class MoodleExcelWorksheet {
  */
 class MoodleExcelFormat {
     /** @var array */
-    protected $format = array('font'=>array('size'=>10, 'name'=>'Arial'));
+    protected $format = array();
 
     /**
      * Constructs one Moodle Format.