diff --git a/skin.module b/skin.module
index a1d1bc96e161cb3bad95b00c9a9af3f8a89dc585..aaaf8297dec0c8bfdef6031bf8186808a99d33fb 100755
--- a/skin.module
+++ b/skin.module
@@ -83,7 +83,18 @@ function _skin_replace_callback($matches) {
       $skin_path = file_create_path('skin') . (!$optimized ? '/'. dirname($filepath_minus_query) : '');
       if (file_check_directory($skin_path, FILE_CREATE_DIRECTORY) or mkdir($skin_path, 0755, TRUE)) {
         $filename = $skin_path .'/'. $info['filename'] .'.'. $info['extension'];
-        $contents = file_get_contents($filepath_minus_query);
+        // Optimized files have already resolved imports and prefixed paths.
+        if ($optimized) {
+          $contents = file_get_contents($filepath_minus_query);
+        }
+        // Unoptimized files need to resolve imports and prefix paths.
+        // See drupal_build_css_cache().
+        else {
+          $contents = drupal_load_stylesheet($filepath_minus_query);
+          $base = base_path() . dirname($filepath_minus_query) .'/';
+          _drupal_build_css_path(NULL, $base);
+          $contents = preg_replace_callback('/url\([\'"]?(?![a-z]+:|\/+)([^\'")]+)[\'"]?\)/i', '_drupal_build_css_path', $contents);
+        }
         if (!file_save_data($contents, $filename, FILE_EXISTS_REPLACE)) {
           unset($filename);
         }