diff --git a/ChangeLog b/ChangeLog
index ff7d02b44..22005fbb9 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2010-05-27  Colin Watson  <cjwatson@ubuntu.com>
+
+	* util/grub-mkrescue.in: Initialise override_dir rather than
+	assuming that it's unset or empty in the environment.
+
 2010-05-26  Grégoire Sutre  <gregoire.sutre@gmail.com>
 
 	* kern/emu/hostdisk.c (find_partition_start) [__NetBSD__]: Renamed
diff --git a/util/grub-mkrescue.in b/util/grub-mkrescue.in
index 7e7253006..99b10de7b 100644
--- a/util/grub-mkrescue.in
+++ b/util/grub-mkrescue.in
@@ -37,6 +37,7 @@ pc_dir=${libdir}/$(echo ${PACKAGE_TARNAME} | sed ${transform})/i386-pc
 efi32_dir=${libdir}/$(echo ${PACKAGE_TARNAME} | sed ${transform})/i386-efi
 efi64_dir=${libdir}/$(echo ${PACKAGE_TARNAME} | sed ${transform})/x86_64-efi
 rom_directory=
+override_dir=
 grub_mkimage=${bindir}/`echo grub-mkimage | sed ${transform}`
 
 # Usage: usage