diff --git i/compass.drush.inc w/compass.drush.inc
index 7a28e47..e309eee 100644
--- i/compass.drush.inc
+++ w/compass.drush.inc
@@ -273,7 +273,7 @@ abstract class drush_compass_engine implements drush_compass {
    */
   protected function _compass_execute_command($theme_name) {
     // If the theme has a config.rb file it's Compass, if not carry on.
-    if (!($theme_path = drush_core_find_project_path($theme_name)) || !file_exists($theme_path . '/config.rb')) {
+    if (!($theme_path = drush_core_drupal_directory($theme_name)) || !file_exists($theme_path . '/config.rb')) {
       return -1;
     }
     return (int) drush_shell_exec("compass %s %s " . implode(' ', $this->_compass_get_options($this->command)), $this->command, $theme_path);