diff --git a/src/pkg/flag/flag.go b/src/pkg/flag/flag.go
index 14f4d522c6..19a3104553 100644
--- a/src/pkg/flag/flag.go
+++ b/src/pkg/flag/flag.go
@@ -56,7 +56,7 @@
 
 		flag.Bool(...)  // global options
 		flag.Parse()  // parse leading command
-		subcmd := flag.Arg[0]
+		subcmd := flag.Arg(0)
 		switch subcmd {
 			// add per-subcommand options
 		}