fix help message
diff --git a/benchmark/main.go b/benchmark/main.go
index c74db80..d268d72 100644
--- a/benchmark/main.go
+++ b/benchmark/main.go
@@ -36,7 +36,7 @@
 }
 
 func usage() {
-	println("./benchmark commandName [...]")
+	println(os.Args[0] + " commandName [...]")
 	for _, cmd := range cmds {
 		cmd.usage()
 	}