diff --git a/litex/soc/software/demo/demo.py b/litex/soc/software/demo/demo.py
index 3ab3fa90f..fbae89ccf 100755
--- a/litex/soc/software/demo/demo.py
+++ b/litex/soc/software/demo/demo.py
@@ -7,6 +7,7 @@
 # SPDX-License-Identifier: BSD-2-Clause
 
 import os
+import sys
 import argparse
 
 from litex.build.tools import replace_in_file
@@ -23,6 +24,7 @@ def main():
 
     # Copy contents to demo directory
     os.system(f"cp {os.path.abspath(os.path.dirname(__file__))}/* demo")
+    os.system("chmod -R u+w demo")
 
     # Update memory region.
     replace_in_file("demo/linker.ld", "main_ram", args.mem)
@@ -35,7 +37,7 @@ def main():
     os.system("cp demo/demo.bin ./")
 
     # Prepare flash boot image.
-    os.system("python3 -m litex.soc.software.crcfbigen demo.bin -o demo.fbi --fbi --little") # FIXME: Endianness.
+    os.system(f"{sys.executable or 'python3'} -m litex.soc.software.crcfbigen demo.bin -o demo.fbi --fbi --little") # FIXME: Endianness.
 
 if __name__ == "__main__":
     main()