diff --git a/system/core/Common.php b/system/core/Common.php
index 00e3030..cfc63c2 100644
--- a/system/core/Common.php
+++ b/system/core/Common.php
@@ -76,6 +76,7 @@
 	 * the file, based on the read-only attribute. is_writable() is also unreliable
 	 * on Unix servers if safe_mode is on.
 	 *
+	 * @link	https://bugs.php.net/bug.php?id=54709
 	 * @param	string
 	 * @return	void
 	 */