diff --git a/etc/mtree/BSD.include.dist b/etc/mtree/BSD.include.dist
index c2a0e912ace5..637ec037e6e8 100644
--- a/etc/mtree/BSD.include.dist
+++ b/etc/mtree/BSD.include.dist
@@ -102,6 +102,8 @@
         ..
         ciss
         ..
+        filemon
+        ..
         firewire
         ..
         hwpmc
diff --git a/include/Makefile b/include/Makefile
index c67dc75b7f48..d2f6d7f08853 100644
--- a/include/Makefile
+++ b/include/Makefile
@@ -39,7 +39,7 @@ LDIRS=	bsm cam geom net net80211 netatalk netgraph netinet netinet6 \
 	sys vm
 
 LSUBDIRS=	cam/ata cam/scsi \
-	dev/acpica dev/an dev/bktr dev/ciss dev/firewire dev/hwpmc \
+	dev/acpica dev/an dev/bktr dev/ciss dev/filemon dev/firewire dev/hwpmc \
 	dev/ic dev/iicbus ${_dev_ieee488} dev/io dev/lmc dev/mfi dev/ofw \
 	dev/pbio ${_dev_powermac_nvram} dev/ppbus dev/smbus \
 	dev/speaker dev/usb dev/utopia dev/vkbd dev/wi \