diff -Nurp a/harness/cases/22.t b/harness/cases/22.t
--- a/harness/cases/22.t	2018-10-22 20:59:34.000000000 +0100
+++ b/harness/cases/22.t	2022-02-26 09:48:59.421311473 +0000
@@ -11,7 +11,7 @@
 #include <signal.h>
 #include <stdio.h>
 #include <unistd.h>
-#include <sys/poll.h>
+#include <poll.h>
 #include <sys/wait.h>
 #include <stdlib.h>