diff --git a/p2p/net/mock/mock_stream.go b/p2p/net/mock/mock_stream.go
index c680ead26dc35b17b1c64ece652c0418938c251f..8d01505049762f8baa04aedf57d1c00dc9c54643 100644
--- a/p2p/net/mock/mock_stream.go
+++ b/p2p/net/mock/mock_stream.go
@@ -64,7 +64,7 @@ func (s *stream) Write(p []byte) (n int, err error) {
 	select {
 	case <-s.closed: // bail out if we're closing.
 		return 0, s.writeErr
-	case s.toDeliver <- &transportObject{msg: p, arrivalTime: t}:
+	case s.toDeliver <- &transportObject{msg: cpy, arrivalTime: t}:
 	}
 	return len(p), nil
 }