diff --git a/sys/conf/files.amd64 b/sys/conf/files.amd64
index 3176469f75d6..19534743bdda 100644
--- a/sys/conf/files.amd64
+++ b/sys/conf/files.amd64
@@ -69,6 +69,7 @@ amd64/amd64/mpboot.S		optional	smp
 amd64/amd64/mptable.c		optional	mptable
 amd64/amd64/mptable_pci.c	optional	mptable pci
 amd64/amd64/nexus.c		standard
+amd64/amd64/prof_machdep.c	optional	profiling-routine
 amd64/amd64/pmap.c		standard
 amd64/amd64/sigtramp.S		standard
 amd64/amd64/support.S		standard