diff --git a/common/turbotunnel/queuepacketconn_test.go b/common/turbotunnel/queuepacketconn_test.go
index 30e69e3..2934971 100644
--- a/common/turbotunnel/queuepacketconn_test.go
+++ b/common/turbotunnel/queuepacketconn_test.go
@@ -208,14 +208,16 @@ func TestQueuePacketConnWriteToKCP(t *testing.T) {
 			panic(err)
 		}
 
+		// A sleep after the Write makes buffer reuse more likely, and is needed
+		// to allow time for flushing all bytes written to the connection before close.
+		// This is not guaranteed by kcp-go. See https://github.com/xtaci/kcp-go/issues/273
+		time.Sleep(100 * time.Millisecond)
+
 		err = conn.Close()
 		if err != nil {
 			panic(err)
 		}
 
-		// A sleep after the Write makes buffer reuse more likely.
-		time.Sleep(100 * time.Millisecond)
-
 		if len(transcript.Transcript) == 0 {
 			panic("empty transcript")
 		}