diff --git a/p/f.php b/p/f.php
index 81df8984b..b68109cd5 100644
--- a/p/f.php
+++ b/p/f.php
@@ -28,7 +28,7 @@ $txt_mtime = @filemtime($txt);
 
 header('Content-Type: image/x-icon');
 
-if ($ico_mtime == false || $ico_mtime < $txt_mtime || ($ico_mtime < time() - (rand(15, 20) * 86400))) {
+if ($ico_mtime == false || $ico_mtime < $txt_mtime || ($ico_mtime < time() - (mt_rand(15, 20) * 86400))) {
 	if ($txt_mtime == false) {
 		show_default_favicon(1800);
 		exit();
@@ -49,6 +49,6 @@ if ($ico_mtime == false || $ico_mtime < $txt_mtime || ($ico_mtime < time() - (ra
 
 header('Content-Disposition: inline; filename="' . $id . '.ico"');
 
-if (!httpConditional($ico_mtime, rand(14, 21) * 86400, 2)) {
+if (!httpConditional($ico_mtime, mt_rand(14, 21) * 86400, 2)) {
 	readfile($ico);
 }