diff --git a/modules/caddyhttp/reverseproxy/streaming.go b/modules/caddyhttp/reverseproxy/streaming.go
index ccb056d58..d664e66d8 100644
--- a/modules/caddyhttp/reverseproxy/streaming.go
+++ b/modules/caddyhttp/reverseproxy/streaming.go
@@ -213,15 +213,15 @@ func (h *Handler) handleUpgradeResponse(logger *zap.Logger, rw http.ResponseWrit
 	start := time.Now()
 
 	if !detached {
-		h.handleUpgradeTunnel(streamLogger, streamLevel, conn, backConn, deleteFrontConn, deleteBackConn, bufferSize, streamTimeout, start, finishMetrics, streamFields)
+		handleUpgradeTunnel(streamLogger, streamLevel, conn, backConn, deleteFrontConn, deleteBackConn, bufferSize, streamTimeout, start, finishMetrics, streamFields)
 	} else {
 		// start a new goroutine
-		go h.handleUpgradeTunnel(streamLogger, streamLevel, conn, backConn, deleteFrontConn, deleteBackConn, bufferSize, streamTimeout, start, finishMetrics, streamFields)
+		go handleUpgradeTunnel(streamLogger, streamLevel, conn, backConn, deleteFrontConn, deleteBackConn, bufferSize, streamTimeout, start, finishMetrics, streamFields)
 	}
 }
 
 // handleUpgradeTunnel returns when transfer is done.
-func (h *Handler) handleUpgradeTunnel(streamLogger *zap.Logger, streamLevel zapcore.Level, conn io.ReadWriteCloser, backConn io.ReadWriteCloser, deleteFrontConn func(), deleteBackConn func(), bufferSize int, streamTimeout time.Duration, start time.Time, finishMetrics func(result string, duration time.Duration, toBackend int64, fromBackend int64), streamFields []zap.Field) {
+func handleUpgradeTunnel(streamLogger *zap.Logger, streamLevel zapcore.Level, conn io.ReadWriteCloser, backConn io.ReadWriteCloser, deleteFrontConn func(), deleteBackConn func(), bufferSize int, streamTimeout time.Duration, start time.Time, finishMetrics func(result string, duration time.Duration, toBackend int64, fromBackend int64), streamFields []zap.Field) {
 	defer deleteBackConn()
 	defer deleteFrontConn()
 	var (