diff --git a/targets/buildtarget b/targets/buildtarget
index f519fd36b7..7c7dc626d3 100755
--- a/targets/buildtarget
+++ b/targets/buildtarget
@@ -16,7 +16,8 @@ fi
 
 target_dir=$lbpath/targets
 config_lb=$1/Config.lb
-config_py=$lbpath/util/newconfig/config.py
+config_dir=$lbpath/util/newconfig
+config_py=$config_dir/config.py
 
 if [ ! -d $target_dir ]; then
 	echo "Target directory not found"
@@ -35,6 +36,10 @@ if [ ! -f $config_py ]; then
 	exit 1
 fi
 
+# make sure config.py is up-to-date
+
+(cd $config_dir && make config.py)
+
 python $config_py $config_lb $lbpath
 
 exit $?