diff --git a/server-tools/instance-manager/thread_registry.cc b/server-tools/instance-manager/thread_registry.cc
index 489caa0aaa8..087f16dc956 100644
--- a/server-tools/instance-manager/thread_registry.cc
+++ b/server-tools/instance-manager/thread_registry.cc
@@ -21,6 +21,7 @@
 #include <thr_alarm.h>
 #include <signal.h>
 #include "log.h"
+#include <my_sys.h>
 
 #ifndef __WIN__
 /* Kick-off signal handler */