diff --git a/libbeat/outputs/logstash/async.go b/libbeat/outputs/logstash/async.go
index c041804459a..f092ff8a627 100644
--- a/libbeat/outputs/logstash/async.go
+++ b/libbeat/outputs/logstash/async.go
@@ -165,6 +165,7 @@ func (r *msgRef) callback(seq uint32, err error) {
 func (r *msgRef) done(n uint32) {
 	ackedEvents.Add(int64(n))
 	r.batch = r.batch[n:]
+	r.win.tryGrowWindow(r.batchSize)
 	r.dec()
 }
 
@@ -172,6 +173,7 @@ func (r *msgRef) fail(n uint32, err error) {
 	ackedEvents.Add(int64(n))
 	r.err = err
 	r.batch = r.batch[n:]
+	r.win.shrinkWindow()
 	r.dec()
 }
 
@@ -184,10 +186,8 @@ func (r *msgRef) dec() {
 	err := r.err
 	if err != nil {
 		eventsNotAcked.Add(int64(len(r.batch)))
-		r.win.shrinkWindow()
 		r.cb(r.batch, err)
 	} else {
-		r.win.tryGrowWindow(r.batchSize)
 		r.cb(nil, nil)
 	}
 }