--- moreutils-0.67/pee.c.orig	2021-12-21 20:39:00.000000000 +0100
+++ moreutils-0.67/pee.c	2023-05-01 11:12:35.161427781 +0200
@@ -5,6 +5,7 @@
 #include <sys/types.h>
 #include <sys/wait.h>
 #include <errno.h>
+#include <signal.h>
 
 /* Licensed under the GPL
  * Copyright (c) Miek Gieben, 2006