diff --git a/transport/sudoku/obfs/httpmask/tunnel.go b/transport/sudoku/obfs/httpmask/tunnel.go
index fc91c5fb..b4c880bb 100644
--- a/transport/sudoku/obfs/httpmask/tunnel.go
+++ b/transport/sudoku/obfs/httpmask/tunnel.go
@@ -501,6 +501,7 @@ func (c *streamSplitConn) pullLoop() {
 				case c.rxc <- payload:
 				case <-c.closed:
 					_ = resp.Body.Close()
+					cancel()
 					return
 				}
 			}