diff --git a/wp-includes/rewrite.php b/wp-includes/rewrite.php
index 51ce2e201..7d23fc5c6 100644
--- a/wp-includes/rewrite.php
+++ b/wp-includes/rewrite.php
@@ -447,8 +447,9 @@ class WP_Rewrite {
 		}
 
 		if (empty($this->category_base))
-			$this->category_base = 'category';
-		$this->category_structure = trailingslashit( $this->front . $this->category_base );
+			$this->category_structure = trailingslashit( $this->front . 'category' );
+		else
+			$this->category_structure = trailingslashit( '/' . $this->root . $this->category_base );
 
 		$this->category_structure .= '%category%';
 
@@ -466,8 +467,9 @@ class WP_Rewrite {
 		}
 
 		if (empty($this->tag_base))
-			$this->tag_base = 'tag';
-		$this->tag_structure = trailingslashit( $this->front . $this->tag_base );
+			$this->tag_structure = trailingslashit( $this->front . 'tag' );
+		else
+			$this->tag_structure = trailingslashit( '/' . $this->root . $this->tag_base );
 
 		$this->tag_structure .= '%tag%';
 
diff --git a/wp-includes/version.php b/wp-includes/version.php
index ddd110844..71d3f6279 100644
--- a/wp-includes/version.php
+++ b/wp-includes/version.php
@@ -15,6 +15,6 @@ $wp_version = '2.7-bleeding';
  *
  * @global int $wp_db_version
  */
-$wp_db_version = 8585;
+$wp_db_version = 8586;
 
 ?>