diff --git a/imagecache.module b/imagecache.module
index aa63b66..a22eade 100644
--- a/imagecache.module
+++ b/imagecache.module
@@ -399,16 +399,10 @@ function imagecache_create_url($presetname, $filepath, $bypass_browser_cache = F
  */
 function imagecache_style_path_token($presetname, $path) {
   // Drupal 6 may not yet have drupal_get_hash_salt().
-  global $databases;
-  $salt = hash('sha256', serialize($databases));
+  global $db_url;
+  $salt = hash('sha256', serialize($db_url));
   // Return the first eight characters.
-  return substr(_imagecache_hmac_base64($presetname . ':' . $path, drupal_get_private_key() . $salt), 0, 8);
-}
-
-function _imagecache_hmac_base64($data, $key) {
-  $hmac = base64_encode(hash_hmac('sha256', $data, $key, TRUE));
-  // Modify the hmac so it's safe to use in URLs.
-  return strtr($hmac, array('+' => '-', '/' => '_', '=' => ''));
+  return substr(sha1($presetname . ':' . $path . drupal_get_private_key() . $salt), 0, 8);
 }
 
 /**