diff --git a/mod/data/field/radiobutton/field.class.php b/mod/data/field/radiobutton/field.class.php
index 2cf8827dd2c..416ccc6a726 100644
--- a/mod/data/field/radiobutton/field.class.php
+++ b/mod/data/field/radiobutton/field.class.php
@@ -103,7 +103,8 @@ class data_field_radiobutton extends data_field_base {
         }
         $return = html_writer::label(get_string('fieldtypelabel', "datafield_" . $this->type),
             'menuf_' . $this->field->id, false, array('class' => 'accesshide'));
-        $return .= html_writer::select($options, 'f_'.$this->field->id, $value, null, array('class' => 'custom-select'));
+        $return .= html_writer::select($options, 'f_'.$this->field->id, $value,
+            array('' => 'choosedots'), array('class' => 'custom-select'));
         return $return;
     }