Index: wp-includes/comment-template.php
===================================================================
--- wp-includes/comment-template.php	(revision 36342)
+++ wp-includes/comment-template.php	(working copy)
@@ -1242,7 +1242,7 @@
  * @global int        $user_ID
  * @global string     $user_identity
  * @global bool       $overridden_cpage
- * @global bool       $withcomments 
+ * @global bool       $withcomments
  *
  * @param string $file              Optional. The file to load. Default '/comments.php'.
  * @param bool   $separate_comments Optional. Whether to separate the comments by comment type.
@@ -2135,7 +2135,7 @@
 	$fields = apply_filters( 'comment_form_default_fields', $fields );
 	$defaults = array(
 		'fields'               => $fields,
-		'comment_field'        => '<p class="comment-form-comment"><label for="comment">' . _x( 'Comment', 'noun' ) . '</label> <textarea id="comment" name="comment" cols="45" rows="8" maxlength="65525" aria-required="true" required="required"></textarea></p>',
+		'comment_field'        => '<p class="comment-form-comment"><label for="comment">' . _x( 'Comment', 'noun' ) . ' <span class="required">*</span></label> <textarea id="comment" name="comment" cols="45" rows="8" maxlength="65525" aria-required="true" required="required"></textarea></p>',
 		/** This filter is documented in wp-includes/link-template.php */
 		'must_log_in'          => '<p class="must-log-in">' . sprintf( __( 'You must be <a href="%s">logged in</a> to post a comment.' ), wp_login_url( apply_filters( 'the_permalink', get_permalink( $post_id ) ) ) ) . '</p>',
 		/** This filter is documented in wp-includes/link-template.php */