diff --git a/Makefile b/Makefile
index e1162c58b..53bf87350 100644
--- a/Makefile
+++ b/Makefile
@@ -87,7 +87,7 @@ dsk: md asm
 	$(CADIUS) ADDFOLDER build/"$(DISK)" "/$(VOLUME)/X" "build/X" >>build/log
 	bin/buildfileinfo.sh build/PRELAUNCH "06" "0106" >>build/log
 	$(CADIUS) ADDFOLDER build/"$(DISK)" "/$(VOLUME)/PRELAUNCH" "build/PRELAUNCH" >>build/log
-	bin/changebootloader.py build/"$(DISK)" res/proboothd
+	bin/changebootloader.sh build/"$(DISK)" res/proboothd
 
 asm: md asmlauncher asmfx asmprelaunch
 
diff --git a/bin/changebootloader.py b/bin/changebootloader.py
deleted file mode 100755
index 87e59d366..000000000
--- a/bin/changebootloader.py
+++ /dev/null
@@ -1,15 +0,0 @@
-#!/usr/bin/env python3
-
-import sys
-import os.path
-
-target_2mg_file, bootloader = sys.argv[1:]
-assert(os.path.splitext(target_2mg_file)[-1].lower() == ".2mg")
-with open(bootloader, 'rb') as f:
-    boot = f.read()
-assert(len(boot) == 512)
-with open(target_2mg_file, 'rb') as f:
-    data = bytearray(f.read())
-data[64:64+len(boot)] = boot
-with open(target_2mg_file, 'wb') as f:
-    f.write(data)
diff --git a/bin/changebootloader.sh b/bin/changebootloader.sh
new file mode 100755
index 000000000..9f4b8c6d4
--- /dev/null
+++ b/bin/changebootloader.sh
@@ -0,0 +1,3 @@
+#!/bin/sh
+
+dd of="$1" bs=1 seek=64 count=512 conv=notrunc < "$2"