diff --git a/src/ch/ch_events.c b/src/ch/ch_events.c
index ba5b247c83..1cce30836a 100644
--- a/src/ch/ch_events.c
+++ b/src/ch/ch_events.c
@@ -20,6 +20,8 @@
 
 #include <config.h>
 
+#include <unistd.h>
+
 #include "ch_domain.h"
 #include "ch_events.h"
 #include "ch_process.h"