=== modified file 'initramfs-tools-hook'
--- initramfs-tools-hook	2018-08-19 14:06:55 +0000
+++ initramfs-tools-hook	2020-02-09 17:57:08 +0000
@@ -142,8 +142,9 @@
 # Get DEVICE from initramfs.conf and other files
 . /etc/initramfs-tools/initramfs.conf
 for conf in /etc/initramfs-tools/conf.d/*; do
-    if [ -n `basename \"$conf\" | grep '^[[:alnum:]][[:alnum:]\._-]*$' \
-	| grep -v '\.dpkg-.*$'` ]; then
+    if [ -n "`basename \"$conf\" \
+	| grep '^[[:alnum:]][[:alnum:]\._-]*$' \
+	| grep -v '\.dpkg-.*$'`" ]; then
 	[ -f "${conf}" ] && . "${conf}"
     fi
 done