diff -uNr i3-4.15/src/log.c i3-4.15.mod/src/log.c
--- i3-4.15/src/log.c	2018-03-10 19:29:14.000000000 +0200
+++ i3-4.15.mod/src/log.c	2018-06-21 19:48:29.573587298 +0300
@@ -24,6 +24,8 @@
 #include <pthread.h>
 #endif
 
+#include <posix-shm.h>
+
 #include "util.h"
 #include "log.h"
 #include "i3.h"