diff --git a/wp-includes/plugin.php b/wp-includes/plugin.php
index 945461c..5bc475d 100644
--- a/wp-includes/plugin.php
+++ b/wp-includes/plugin.php
@@ -567,7 +567,11 @@ function plugin_basename($file) {
 	$mu_plugin_dir = str_replace('\\','/',WPMU_PLUGIN_DIR); // sanitize for Win32 installs
 	$mu_plugin_dir = preg_replace('|/+|','/', $mu_plugin_dir); // remove any duplicate slash
 	$file = preg_replace('#^' . preg_quote($plugin_dir, '#') . '/|^' . preg_quote($mu_plugin_dir, '#') . '/#','',$file); // get relative path from plugins dir
-	$file = trim($file, '/');
+	
+	$dir      = basename(dirname($file));
+	$filename = basename($file);
+
+	$file = trim($dir . '/' . $filename, '/');
 	return $file;
 }