diff --git a/kern/ipc_kobject.c b/kern/ipc_kobject.c
index 709ec9e..1d59f0c 100644
--- a/kern/ipc_kobject.c
+++ b/kern/ipc_kobject.c
@@ -56,6 +56,7 @@
 #include <device/device_pager.server.h>
 #include <kern/mach4.server.h>
 #include <kern/gnumach.server.h>
+#include <kern/experimental.server.h>
 
 #if MACH_DEBUG
 #include <kern/mach_debug.server.h>