diff --git a/core/SConscript.firmware b/core/SConscript.firmware
index f00a89401..7019b46ec 100644
--- a/core/SConscript.firmware
+++ b/core/SConscript.firmware
@@ -627,6 +627,7 @@ if env.get('TREZOR_MODEL') == 'T':
 else:
     action_bin=[
         '$OBJCOPY -O binary -j .header -j .flash -j .data $SOURCE $TARGET',
+        '../legacy/bootloader/firmware_sign.py -f $TARGET',
     ]
 
 program_bin = env.Command(