diff --git a/playground/socket/socket.go b/playground/socket/socket.go
index c7843e59734..99558f7979b 100644
--- a/playground/socket/socket.go
+++ b/playground/socket/socket.go
@@ -369,7 +369,7 @@ func (p *process) start(body string, opt *Options) error {
 
 	// write body to x.go files
 	a := txtar.Parse([]byte(body))
-	if len(a.Comment) != 0 {
+	if strings.TrimSpace(string(a.Comment)) != "" {
 		a.Files = append(a.Files, txtar.File{Name: "prog.go", Data: a.Comment})
 		a.Comment = nil
 	}