diff --git a/scripts/buildcommands.py b/scripts/buildcommands.py
index 8b9cc9d8..6bb47341 100644
--- a/scripts/buildcommands.py
+++ b/scripts/buildcommands.py
@@ -71,7 +71,7 @@ def build_parser(parser, iscmd, all_param_types):
                     + types.count('PT_buffer'))
         out += "    .num_args=%d," % (num_args,)
     else:
-        max_size = min(msgproto.MESSAGE_MAX
+        max_size = min(msgproto.MESSAGE_MAX - msgproto.MESSAGE_MIN
                        , 1 + sum([t.max_length for t in parser.param_types]))
         out += "    .max_size=%d," % (max_size,)
     return out