diff --git a/src/args.rs b/src/args.rs
index 9b07992..fff65ea 100644
--- a/src/args.rs
+++ b/src/args.rs
@@ -8,7 +8,7 @@ fn hex_address(a: &str) -> Result<u16, std::num::ParseIntError> {
 }
 
 #[derive(Parser, Debug)]
-#[command(version, about, long_about = None, next_line_help = true)]
+#[command(version, about, long_about = None, next_line_help = true, arg_required_else_help(true))]
 pub struct Args {
     /// The linux i2c device file, something like /dev/i2c-*.
     #[arg(short, long)]