diff --git a/sys/conf/files b/sys/conf/files
index b72881f8b04e..8da461bdec2e 100644
--- a/sys/conf/files
+++ b/sys/conf/files
@@ -1040,6 +1040,7 @@ kern/kern_tc.c		standard
 kern/kern_thread.c	standard
 kern/kern_time.c	standard
 kern/kern_timeout.c	standard
+kern/kern_umtx.c	standard
 kern/kern_uuid.c	standard
 kern/kern_xxx.c		standard
 kern/link_elf.c		standard