diff --git a/tools/boot/squeeze/boot-x86 b/tools/boot/squeeze/boot-x86
index da68b5eb..24a8cea7 100644
--- a/tools/boot/squeeze/boot-x86
+++ b/tools/boot/squeeze/boot-x86
@@ -208,6 +208,11 @@ if [ "$THISTYPE" = "isolinux" ]; then
 	# Isolinux setup including config and help files comes from d-i.
 	cat cdrom/debian-cd_info.tar.gz | (cd boot$N/isolinux/; tar zx)
 
+	if [ "$(di_config_version)" = "1.0" ]; then
+		echo "Error: syslinux config version 1.0 is no longer supported"
+		exit 1
+	fi
+
 	# Not everything in the tarball is isolinux stuff
 	if [ -e boot$N/isolinux/win32-loader.ini ] ; then
 		mv boot$N/isolinux/g2ldr* boot$N/isolinux/setup.exe \
diff --git a/tools/boot/squeeze/x86-desktop.sh b/tools/boot/squeeze/x86-desktop.sh
index f6c99010..ff0e9e8e 100644
--- a/tools/boot/squeeze/x86-desktop.sh
+++ b/tools/boot/squeeze/x86-desktop.sh
@@ -1,6 +1,15 @@
 # Functions to convert isolinux config to allow selection of desktop
 # environment for certain images.
 
+di_config_version() {
+	local version
+	version=$(sed -nr "s/^# D-I config version ([0-9.])/\1/p" \
+		boot$N/isolinux/isolinux.cfg)
+
+	[ -n "Sversion" ] || return 1
+	echo "$version"
+}
+
 # Workaround for #505243
 # Syslinux does not correctly handle a default64 option in combination
 # with vesamenu. Instead, add special default label to automatically