Index: wp-admin/options-discussion.php
===================================================================
--- wp-admin/options-discussion.php	(revision 20468)
+++ wp-admin/options-discussion.php	(working copy)
@@ -78,15 +78,8 @@
 <?php
 
 $maxdeep = (int) apply_filters( 'thread_comments_depth_max', 10 );
+$thread_comments_depth = "</label><input name='thread_comments_depth' type='number' min='2' max='$maxdeep' step='1' id='thread_comments_depth' value='". get_option('thread_comments_depth') ."' />";
 
-$thread_comments_depth = '</label><select name="thread_comments_depth" id="thread_comments_depth">';
-for ( $i = 2; $i <= $maxdeep; $i++ ) {
-	$thread_comments_depth .= "<option value='" . esc_attr($i) . "'";
-	if ( get_option('thread_comments_depth') == $i ) $thread_comments_depth .= " selected='selected'";
-	$thread_comments_depth .= ">$i</option>";
-}
-$thread_comments_depth .= '</select>';
-
 printf( __('Enable threaded (nested) comments %s levels deep'), $thread_comments_depth );
 
 ?><br />