diff --git a/docs/WASI-tutorial.md b/docs/WASI-tutorial.md
index a5b4ef1b65..d8e070e69a 100644
--- a/docs/WASI-tutorial.md
+++ b/docs/WASI-tutorial.md
@@ -139,7 +139,7 @@ fn main() {
     let program = args[0].clone();
 
     if args.len() < 3 {
-        eprintln!("usage: {} <input_file> <output_file>", program);
+        eprintln!("usage: {} <from> <to>", program);
         return;
     }