diff --git a/transport/simple-obfs/tls.go b/transport/simple-obfs/tls.go
index 0c40303..1d84fbf 100644
--- a/transport/simple-obfs/tls.go
+++ b/transport/simple-obfs/tls.go
@@ -27,10 +27,10 @@ type TLSObfs struct {
 func (to *TLSObfs) read(b []byte, discardN int) (int, error) {
 	buf := pool.Get(discardN)
 	_, err := io.ReadFull(to.Conn, buf)
+	pool.Put(buf)
 	if err != nil {
 		return 0, err
 	}
-	pool.Put(buf)
 
 	sizeBuf := make([]byte, 2)
 	_, err = io.ReadFull(to.Conn, sizeBuf)