Index: src/lib-master/test-event-stats.c
--- src/lib-master/test-event-stats.c.orig	2019-12-04 10:31:27.000000000 +0100
+++ src/lib-master/test-event-stats.c	2019-12-12 09:27:14.864844000 +0100
@@ -15,6 +15,7 @@
 #include <fcntl.h>
 #include <unistd.h>
 #include <signal.h>
+#include <sys/types.h>
 #include <sys/socket.h>
 #include <sys/un.h>
 #include <sys/wait.h>