diff --git a/server/socket.go b/server/socket.go
index db1a0e350..3b3c3db6c 100644
--- a/server/socket.go
+++ b/server/socket.go
@@ -122,7 +122,7 @@ func kv(p util.Param) string {
 
 	if p.Key == "" && val == "" {
 		log.ERROR.Printf("invalid key/val for %+v, please report to https://github.com/evcc-io/evcc/issues/6439", p)
-		return "{\"foo\":\"bar\"}"
+		return "\"foo\":\"bar\""
 	}
 
 	var msg strings.Builder