diff --git a/session.go b/session.go
index 559f9aa06..0367bd9da 100644
--- a/session.go
+++ b/session.go
@@ -641,6 +641,7 @@ func (s *Session) garbageCollectStreams() {
 			s.windowUpdateManager.RemoveStream(k)
 		}
 		if v.finished() {
+			utils.Debugf("Garbage-collecting stream %d", k)
 			atomic.AddUint32(&s.openStreamsCount, ^uint32(0)) // decrement
 			s.streams[k] = nil
 		}