diff --git a/includes/common.inc b/includes/common.inc
index 4a63391147a..16309da5b92 100644
--- a/includes/common.inc
+++ b/includes/common.inc
@@ -3,7 +3,7 @@
 function conf_init() {
   global $HTTP_HOST, $REQUEST_URI;
   $file = strtolower(strtr($HTTP_HOST ."". substr($REQUEST_URI, 0, strrpos($REQUEST_URI, "/")), "/:", ".."));
-  while ($file && !file_exists("includes/$file.php")) $file = substr($file, 0, strrpos($file, "."));
+  while ($file && !file_exists("includes/$file.php")) $file = substr($file, strpos($file, ".") + 1);
   return $file ? $file : "conf";
 }