diff --git a/Rakefile b/Rakefile
index 8c62de5..6003671 100644
--- a/Rakefile
+++ b/Rakefile
@@ -199,7 +199,7 @@ BMP_PORT = ENV["BMP_PORT"] || "/dev/ttyACM0"
 
 desc "flash application using USB DFU"
 task :flash => APPLICATION+".bin" do |t|
-  sh "dfu-util -d 1209:4256 -D #{t.source}"
+  sh "dfu-util --device 1209:4256 --download #{t.source}"
 end
 
 desc "flash bootloader using SWD"