diff -Nru initramfs-tools-0.122ubuntu8.12/debian/changelog initramfs-tools-0.122ubuntu8.13/debian/changelog
--- initramfs-tools-0.122ubuntu8.12/debian/changelog	2018-05-16 22:10:19.000000000 +0200
+++ initramfs-tools-0.122ubuntu8.13/debian/changelog	2018-09-12 14:06:58.000000000 +0200
@@ -1,3 +1,10 @@
+initramfs-tools (0.122ubuntu8.13) xenial; urgency=medium
+
+  * debian/initramfs-tools.postinst: remove orphaned old-dkms initrd files
+    in /boot. (LP: #1791959)
+
+ -- Tiago Stürmer Daitx <tiago.daitx@ubuntu.com>  Wed, 12 Sep 2018 12:06:58 +0000
+
 initramfs-tools (0.122ubuntu8.12) xenial; urgency=medium
 
   [ Scott Moser ]
diff -Nru initramfs-tools-0.122ubuntu8.12/debian/initramfs-tools.postinst initramfs-tools-0.122ubuntu8.13/debian/initramfs-tools.postinst
--- initramfs-tools-0.122ubuntu8.12/debian/initramfs-tools.postinst	2016-12-09 18:41:30.000000000 +0100
+++ initramfs-tools-0.122ubuntu8.13/debian/initramfs-tools.postinst	2018-09-12 14:06:58.000000000 +0200
@@ -11,4 +11,21 @@
 	DPKG_MAINTSCRIPT_PACKAGE='' update-initramfs -u
 fi
 
+# Remove all initrd old dkms files for which there is no
+# corresponding initram image in /boot (LP: #1791959).
+# One shot only:
+# - bug only affected users that were upgrading packages
+# - new users are not affected
+# - LP: #1515513 took care of removing old dkms together with the kernel
+if [ "x$1" = xconfigure ] && [ -n "$2" ] && dpkg --compare-versions "$2" lt "0.122ubuntu8.13"; then
+	for old_dkms_file in /boot/initrd-*.img.old-dkms \
+			     /boot/initramfs-*.img.old-dkms \
+			     /boot/initrd.img-*.old-dkms \
+			     /boot/initrd-*.old-dkms; do
+		if [ ! -e "${old_dkms_file%%.old-dkms}" ]; then
+			rm -fv "${old_dkms_file}"
+		fi
+	done
+fi
+
 #DEBHELPER#