diff --git a/pkg/gotd/rpc/ack.go b/pkg/gotd/rpc/ack.go
index f4680377..d53fd5f1 100644
--- a/pkg/gotd/rpc/ack.go
+++ b/pkg/gotd/rpc/ack.go
@@ -10,11 +10,13 @@ func (e *Engine) NotifyAcks(ids []int64) {
 	defer e.mux.Unlock()
 
 	for _, id := range ids {
-		ch, ok := e.ack[id]
-		if !ok {
-			continue
-		}
+		e.notifyAckUnlocked(id)
+	}
+}
 
+func (e *Engine) notifyAckUnlocked(id int64) {
+	ch, ok := e.ack[id]
+	if ok {
 		close(ch)
 		delete(e.ack, id)
 	}
diff --git a/pkg/gotd/rpc/engine.go b/pkg/gotd/rpc/engine.go
index 8cae945e..dc9bcaf0 100644
--- a/pkg/gotd/rpc/engine.go
+++ b/pkg/gotd/rpc/engine.go
@@ -231,6 +231,7 @@ func (e *Engine) retryUntilAck(ctx context.Context, req Request) (sent bool, err
 // NotifyResult notifies engine about received RPC response.
 func (e *Engine) NotifyResult(msgID int64, b *bin.Buffer) error {
 	e.mux.Lock()
+	e.notifyAckUnlocked(msgID)
 	fn, ok := e.rpc[msgID]
 	e.mux.Unlock()
 	if !ok {
@@ -245,6 +246,7 @@ func (e *Engine) NotifyResult(msgID int64, b *bin.Buffer) error {
 func (e *Engine) NotifyError(msgID int64, rpcErr error) {
 	e.onError(rpcErr)
 	e.mux.Lock()
+	e.notifyAckUnlocked(msgID)
 	fn, ok := e.rpc[msgID]
 	e.mux.Unlock()
 	if !ok {