diff --git a/wp-includes/comment-template.php b/wp-includes/comment-template.php
index 41d32788af..ed5092ef55 100644
--- a/wp-includes/comment-template.php
+++ b/wp-includes/comment-template.php
@@ -1495,16 +1495,16 @@ function comment_form( $args = array(), $post_id = null ) {
 	$aria_req = ( $req ? " aria-required='true'" : '' );
 	$fields =  array(
 		'author' => '<p class="comment-form-author">' . '<label for="author">' . __( 'Name' ) . '</label> ' . ( $req ? '<span class="required">*</span>' : '' ) .
-		            '<input id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30" tabindex="1"' . $aria_req . ' /></p>',
+		            '<input id="author" name="author" type="text" value="' . esc_attr( $commenter['comment_author'] ) . '" size="30"' . $aria_req . ' /></p>',
 		'email'  => '<p class="comment-form-email"><label for="email">' . __( 'Email' ) . '</label> ' . ( $req ? '<span class="required">*</span>' : '' ) .
-		            '<input id="email" name="email" type="text" value="' . esc_attr(  $commenter['comment_author_email'] ) . '" size="30" tabindex="2"' . $aria_req . ' /></p>',
+		            '<input id="email" name="email" type="text" value="' . esc_attr(  $commenter['comment_author_email'] ) . '" size="30"' . $aria_req . ' /></p>',
 		'url'    => '<p class="comment-form-url"><label for="url">' . __( 'Website' ) . '</label>' .
-		            '<input id="url" name="url" type="text" value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" tabindex="3" /></p>',
+		            '<input id="url" name="url" type="text" value="' . esc_attr( $commenter['comment_author_url'] ) . '" size="30" /></p>',
 	);
 
 	$defaults = array(
 		'fields'               => apply_filters( 'comment_form_default_fields', $fields ),
-		'comment_field'        => '<p class="comment-form-comment"><label for="comment">' . __( 'Comment' ) . '</label><textarea id="comment" name="comment" cols="45" rows="8" tabindex="4" aria-required="true"></textarea></p>',
+		'comment_field'        => '<p class="comment-form-comment"><label for="comment">' . __( 'Comment' ) . '</label><textarea id="comment" name="comment" cols="45" rows="8" aria-required="true"></textarea></p>',
 		'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( $post_id ) ) ) ) . '</p>',
 		'logged_in_as'         => '<p class="logged-in-as">' . sprintf( __( 'Logged in as <a href="%1$s">%2$s</a>. <a href="%3$s" title="Log out of this account">Log out?</a></p>' ), admin_url( 'profile.php' ), $user_identity, wp_logout_url( apply_filters( 'the_permalink', get_permalink( $post_id ) ) ) ),
 		'comment_notes_before' => '<p class="comment-notes">' . __( 'Your email is <em>never</em> published nor shared.' ) . ( $req ? __( ' Required fields are marked <span class="required">*</span>' ) : '' ) . '</p>',
@@ -1546,7 +1546,7 @@ function comment_form( $args = array(), $post_id = null ) {
 						<?php echo apply_filters( 'comment_form_field_comment', $args['comment_field'] ); ?>
 						<?php echo $args['comment_notes_after']; ?>
 						<p class="form-submit">
-							<input name="submit" type="submit" id="<?php echo esc_attr( $args['id_submit'] ); ?>" tabindex="<?php echo ( count( $args['fields'] ) + 2 ); ?>" value="<?php echo esc_attr( $args['label_submit'] ); ?>" />
+							<input name="submit" type="submit" id="<?php echo esc_attr( $args['id_submit'] ); ?>" value="<?php echo esc_attr( $args['label_submit'] ); ?>" />
 							<?php comment_id_fields(); ?>
 						</p>
 						<?php do_action( 'comment_form', $post_id ); ?>