diff --git a/map_stream.go b/map_stream.go
index 34ffad6..875bc5d 100755
--- a/map_stream.go
+++ b/map_stream.go
@@ -20,6 +20,9 @@ func (m *MapStream) GetStream(key string, ns ...string) (io.Reader, error) {
 }
 
 func (m *MapStream) SetStream(key string, r io.Reader, ns ...string) error {
+	if r == nil {
+		return m.Set(key, nil, ns...)
+	}
 	b, err := ioutil.ReadAll(r)
 	if err != nil {
 		return err