diff -u memtest86+-4.20/debian/changelog memtest86+-4.20/debian/changelog
--- memtest86+-4.20/debian/changelog
+++ memtest86+-4.20/debian/changelog
@@ -1,3 +1,10 @@
+memtest86+ (4.20-1.1ubuntu7) trusty; urgency=low
+
+  * Revert to using linux16 memtest image when using serial console. As
+    knetbsd + elf + serial console does not work. (LP: #560839) 
+
+ -- Dave Chiluk <chiluk@canonical.com>  Thu, 06 Mar 2014 01:07:09 -0600
+
 memtest86+ (4.20-1.1ubuntu6) trusty; urgency=low
 
   [ Rajeev V. Pillai ]
diff -u memtest86+-4.20/debian/grub memtest86+-4.20/debian/grub
--- memtest86+-4.20/debian/grub
+++ memtest86+-4.20/debian/grub
@@ -37,15 +37,21 @@
   cat << EOF
 	knetbsd	$MEMTESTPATH
 }
+EOF
+fi
+
+if test -e /boot/memtest86+.bin ; then
+  MEMTESTPATH=$( make_system_path_relative_to_its_root "/boot/memtest86+.bin" )
+  echo "Found memtest86+ image: $MEMTESTPATH" >&2
+  cat << EOF
 menuentry '$(gettext_printf "Memory test (memtest86+, serial console 115200)")' {
 EOF
   printf '%s\n' "${prepare_boot_cache}"
   cat << EOF
-	knetbsd	$MEMTESTPATH console=ttyS0,115200n8
+	$LX	$MEMTESTPATH console=ttyS0,115200n8
 }
 EOF
 fi
-
 #if test -e /boot/memtest86+_multiboot.bin ; then
 #  MEMTESTPATH=$( make_system_path_relative_to_its_root "/boot/memtest86+_multiboot.bin" )
 #  echo "Found memtest86+ multiboot image: $MEMTESTPATH" >&2