@@ -323,7 +323,7 @@ function upload_image {

         *.vhd|*.vhdx|*.vhd.gz|*.vhdx.gz)

             local extension="${image_fname#*.}"

             image_name=$(basename "$image" ".$extension")

-            disk_format=vhd

+            disk_format=$(echo $image_fname | grep -oP '(?<=\.)vhdx?(?=\.|$)')

             container_format=bare

             if [ "${image_fname##*.}" == "gz" ]; then

                 unpack=zcat