diff --git a/transport/xhttp/client.go b/transport/xhttp/client.go
index f1eae90f..39d0daa7 100644
--- a/transport/xhttp/client.go
+++ b/transport/xhttp/client.go
@@ -136,9 +136,6 @@ func NewClient(cfg *Config, makeTransport TransportMaker, makeDownloadTransport
 	if err != nil {
 		return nil, err
 	}
-	if scMaxEachPostBytes.Max == 0 { // default to 1MB
-		scMaxEachPostBytes.Max = 1000000
-	}
 	ctx, cancel := context.WithCancel(context.Background())
 
 	client := &Client{
diff --git a/transport/xhttp/config.go b/transport/xhttp/config.go
index 0c80b663..f2847072 100644
--- a/transport/xhttp/config.go
+++ b/transport/xhttp/config.go
@@ -114,6 +114,9 @@ func (c *Config) GetNormalizedScMaxEachPostBytes() (Range, error) {
 	if err != nil {
 		return Range{}, fmt.Errorf("invalid sc-max-each-post-bytes: %w", err)
 	}
+	if r.Max == 0 {
+		return Range{}, fmt.Errorf("invalid sc-max-each-post-bytes: must be greater than zero")
+	}
 	return r, nil
 }
 
diff --git a/transport/xhttp/server.go b/transport/xhttp/server.go
index 301e8687..4c68174a 100644
--- a/transport/xhttp/server.go
+++ b/transport/xhttp/server.go
@@ -110,9 +110,6 @@ func NewServerHandler(opt ServerOption) (http.Handler, error) {
 	if err != nil {
 		return nil, err
 	}
-	if scMaxEachPostBytes.Max == 0 { // default to 1MB
-		scMaxEachPostBytes.Max = 1000000
-	}
 	scStreamUpServerSecs, err := opt.Config.GetNormalizedScStreamUpServerSecs()
 	if err != nil {
 		return nil, err