diff --git a/src/main.rs b/src/main.rs
index 03f8ef7..ffcab73 100644
--- a/src/main.rs
+++ b/src/main.rs
@@ -87,6 +87,7 @@ fn parse(str: String) -> u32 {
         Ok(data) => return data,
         Err(e) => {
             eprintln!("Error:${}", e);
+            println!("Note: rust-v4l2 <video_device> <width> <height> <interval>");
             return 0;
         }
     }