diff --git a/quickemu b/quickemu
index 9b65359..3db4db6 100755
--- a/quickemu
+++ b/quickemu
@@ -2016,19 +2016,19 @@ function vm_boot() {
 
         # shellcheck disable=SC2054,SC2206
         args+=(-device ${MAC_DISK_DEV},drive=SystemDisk
-            -drive id=SystemDisk,if=none,format=qcow2,file="${disk_img}",${DRIVE_OPTIMISATIONS} ${STATUS_QUO})
+            -drive id=SystemDisk,if=none,format=${disk_format},file="${disk_img}",${DRIVE_OPTIMISATIONS} ${STATUS_QUO})
     elif [ "${guest_os}" == "kolibrios" ]; then
         # shellcheck disable=SC2054,SC2206
         args+=(-device ahci,id=ahci
             -device ide-hd,bus=ahci.0,drive=SystemDisk
-            -drive id=SystemDisk,if=none,format=qcow2,file="${disk_img}",${DRIVE_OPTIMISATIONS} ${STATUS_QUO})
+            -drive id=SystemDisk,if=none,format=${disk_format},file="${disk_img}",${DRIVE_OPTIMISATIONS} ${STATUS_QUO})
 
     elif [ "${guest_os}" == "batocera" ] ; then
         # shellcheck disable=SC2054,SC2206
         args+=(-device virtio-blk-pci,drive=BootDisk
             -drive id=BootDisk,if=none,format=raw,file="${img}"
             -device virtio-blk-pci,drive=SystemDisk
-            -drive id=SystemDisk,if=none,format=qcow2,file="${disk_img}",${DRIVE_OPTIMISATIONS} ${STATUS_QUO})
+            -drive id=SystemDisk,if=none,format=${disk_format},file="${disk_img}",${DRIVE_OPTIMISATIONS} ${STATUS_QUO})
 
     elif [ "${guest_os}" == "reactos" ]; then
         # https://reactos.org/wiki/QEMU
@@ -2038,7 +2038,7 @@ function vm_boot() {
     elif [ "${guest_os}" == "windows-server" ]; then
         # shellcheck disable=SC2054,SC2206
         args+=(-device ide-hd,drive=SystemDisk
-            -drive id=SystemDisk,if=none,format=qcow2,file="${disk_img}",${DRIVE_OPTIMISATIONS} ${STATUS_QUO})
+            -drive id=SystemDisk,if=none,format=${disk_format},file="${disk_img}",${DRIVE_OPTIMISATIONS} ${STATUS_QUO})
 
     else
         if [ "${ARCH_VM}" == "aarch64" ]; then