diff --git a/v2/var.go b/v2/var.go
index c60a9d2..2f42740 100644
--- a/v2/var.go
+++ b/v2/var.go
@@ -92,7 +92,7 @@ func (s *Set) addFlag(p Value, name string, short rune, helpvalue ...string) Opt
 		opt.where = where
 	}
 	if opt.short == 0 && opt.long == "" {
-		fmt.Fprintf(stderr, opt.where+": no short or long option given")
+		fmt.Fprint(stderr, opt.where+": no short or long option given")
 		exit(1)
 	}
 	s.AddOption(opt)
diff --git a/var.go b/var.go
index fd816b9..f4d8cfc 100644
--- a/var.go
+++ b/var.go
@@ -55,7 +55,7 @@ func (s *Set) VarLong(p Value, name string, short rune, helpvalue ...string) Opt
 		opt.where = fmt.Sprintf("%s:%d", file, line)
 	}
 	if opt.short == 0 && opt.long == "" {
-		fmt.Fprintf(stderr, opt.where+": no short or long option given")
+		fmt.Fprint(stderr, opt.where+": no short or long option given")
 		exit(1)
 	}
 	s.AddOption(opt)