diff --git a/prog/netcheck/netcheck.go b/prog/netcheck/netcheck.go
index 85f6003b..96a26ed4 100644
--- a/prog/netcheck/netcheck.go
+++ b/prog/netcheck/netcheck.go
@@ -10,7 +10,7 @@ import (
 )
 
 func fatal(err error) {
-	fmt.Println(err)
+	fmt.Fprintln(os.Stderr, err)
 	os.Exit(1)
 }