diff --git a/src/pkg/flag/flag.go b/src/pkg/flag/flag.go
index ea6c82f619..0483425f0b 100644
--- a/src/pkg/flag/flag.go
+++ b/src/pkg/flag/flag.go
@@ -260,7 +260,7 @@ var Usage = func() {
 
 var panicOnError = false
 
-// failf prints to standard output a formatted error and Usage, and then exits the program.
+// failf prints to standard error a formatted error and Usage, and then exits the program.
 func failf(format string, a ...interface{}) {
 	fmt.Fprintf(os.Stderr, format, a...)
 	Usage()