diff --git a/wp-includes/category-template.php b/wp-includes/category-template.php
index 07cb666f7c..039a125e17 100644
--- a/wp-includes/category-template.php
+++ b/wp-includes/category-template.php
@@ -85,10 +85,13 @@ function get_the_category_by_ID($cat_ID) {
 }
 
 function get_the_category_list($separator = '', $parents='') {
+	global $wp_rewrite;
 	$categories = get_the_category();
 	if (empty($categories))
 		return apply_filters('the_category', __('Uncategorized'), $separator, $parents);
 
+	$rel = ( is_object($wp_rewrite) && $wp_rewrite->using_permalinks() ) ? 'rel="category tag"' : 'rel="category"';
+
 	$thelist = '';
 	if ( '' == $separator ) {
 		$thelist .= '<ul class="post-categories">';
@@ -98,17 +101,17 @@ function get_the_category_list($separator = '', $parents='') {
 				case 'multiple':
 					if ($category->category_parent)
 						$thelist .= get_category_parents($category->category_parent, TRUE);
-					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" rel="category tag">'.$category->cat_name.'</a></li>';
+					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" ' . $rel . '">' . $category->cat_name.'</a></li>';
 					break;
 				case 'single':
-					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . ' rel="category tag">';
+					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" ' . $rel . '">';
 					if ($category->category_parent)
 						$thelist .= get_category_parents($category->category_parent, FALSE);
 					$thelist .= $category->cat_name.'</a></li>';
 					break;
 				case '':
 				default:
-					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" rel="category tag">'.$category->cat_name.'</a></li>';
+					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" ' . $rel . '">' . $category->cat_name.'</a></li>';
 			}
 		}
 		$thelist .= '</ul>';
@@ -121,17 +124,17 @@ function get_the_category_list($separator = '', $parents='') {
 				case 'multiple':
 					if ( $category->category_parent )
 						$thelist .= get_category_parents($category->category_parent, TRUE);
-					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" rel="category tag">'.$category->cat_name.'</a>';
+					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" ' . $rel . '">' . $category->cat_name.'</a>';
 					break;
 				case 'single':
-					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" rel="category tag">';
+					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" ' . $rel . '">';
 					if ( $category->category_parent )
 						$thelist .= get_category_parents($category->category_parent, FALSE);
 					$thelist .= "$category->cat_name</a>";
 					break;
 				case '':
 				default:
-					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" rel="category tag">'.$category->cat_name.'</a>';
+					$thelist .= '<a href="' . get_category_link($category->cat_ID) . '" title="' . sprintf(__("View all posts in %s"), $category->cat_name) . '" ' . $rel . '">' . $category->cat_name.'</a>';
 			}
 			++$i;
 		}