diff --git a/internal/congestion/cubic_sender.go b/internal/congestion/cubic_sender.go
index 07f6cbd3..936fb4cc 100644
--- a/internal/congestion/cubic_sender.go
+++ b/internal/congestion/cubic_sender.go
@@ -277,4 +277,5 @@ func (c *cubicSender) maybeTraceStateChange(new logging.CongestionState) {
 		return
 	}
 	c.tracer.UpdatedCongestionState(new)
+	c.lastState = new
 }