diff --git a/index.php b/index.php
index 5f3af5b55..413028afa 100644
--- a/index.php
+++ b/index.php
@@ -15,6 +15,7 @@ $timestamps[] = @filemtime("include/prepend.inc");
 $timestamps[] = @filemtime("include/pregen-confs.inc");
 $timestamps[] = @filemtime("include/pregen-news.inc");
 $timestamps[] = @filemtime("include/version.inc");
+$timestamps[] = @filemtime("js/common.js");
 
 // The latest of these modification dates is our real Last-Modified date
 $timestamp = max($timestamps);