diff --git a/src/boot.sh b/src/boot.sh
index d866bd3..1e1bee7 100644
--- a/src/boot.sh
+++ b/src/boot.sh
@@ -40,12 +40,14 @@ DEST="$STORAGE/${BOOT_MODE,,}"
 
 if [ ! -f "$DEST.rom" ]; then
   [ ! -f "$AAVMF/$ROM" ] && error "UEFI boot file ($AAVMF/$ROM) not found!" && exit 44
-  cp "$AAVMF/$ROM" "$DEST.rom"
+  dd if=/dev/zero "of=$DEST.rom" bs=1M count=64 status=none
+  dd "if=$AAVMF/$ROM" "of=$DEST.rom" conv=notrunc status=none
 fi
 
 if [ ! -f "$DEST.vars" ]; then
   [ ! -f "$AAVMF/$VARS" ] && error "UEFI vars file ($AAVMF/$VARS) not found!" && exit 45
-  cp "$AAVMF/$VARS" "$DEST.vars"
+  dd if=/dev/zero "of=$DEST.vars" bs=1M count=64 status=none
+  dd "if=$AAVMF/$VARS" "of=$DEST.vars" conv=notrunc status=none
 fi
 
 BOOT_OPTS="$BOOT_OPTS -drive file=$DEST.rom,if=pflash,unit=0,format=raw,readonly=on"