diff --git a/tools/tools/nanobsd/nanobsd.sh b/tools/tools/nanobsd/nanobsd.sh
index 9d3b9e559d01..054de5c7e008 100644
--- a/tools/tools/nanobsd/nanobsd.sh
+++ b/tools/tools/nanobsd/nanobsd.sh
@@ -75,6 +75,9 @@ NANO_KERNEL=GENERIC
 # Customize commands.
 NANO_CUSTOMIZE=""
 
+# Late customize commands.
+NANO_LATE_CUSTOMIZE=""
+
 # Newfs paramters to use
 NANO_NEWFS="-b 4096 -f 512 -i 8192 -O1 -U"
 
@@ -245,6 +248,18 @@ run_customize() (
 	done
 )
 
+run_late_customize() (
+
+	echo "## run late customize scripts"
+	for c in $NANO_LATE_CUSTOMIZE
+	do
+		echo "## late customize \"$c\""
+		echo "### log: ${MAKEOBJDIRPREFIX}/_.late_cust.$c"
+		echo "### `type $c`"
+		( $c ) > ${MAKEOBJDIRPREFIX}/_.late_cust.$c 2>&1
+	done
+)
+
 setup_nanobsd ( ) (
 	echo "## configure nanobsd setup"
 	echo "### log: ${MAKEOBJDIRPREFIX}/_.dl"
@@ -569,6 +584,15 @@ customize_cmd () {
 	NANO_CUSTOMIZE="$NANO_CUSTOMIZE $1"
 }
 
+#######################################################################
+# Convenience function:
+# 	Register $1 as late customize function to run just before
+#	image creation.
+
+late_customize_cmd () {
+	NANO_LATE_CUSTOMIZE="$NANO_LATE_CUSTOMIZE $1"
+}
+
 #######################################################################
 #
 # All set up to go...
@@ -717,6 +741,7 @@ install_kernel
 run_customize
 setup_nanobsd
 prune_usr
+run_late_customize
 if $do_image ; then
 	create_${NANO_ARCH}_diskimage
 else