diff --git a/server/consumer.go b/server/consumer.go
index 43efb274..38e24f5f 100644
--- a/server/consumer.go
+++ b/server/consumer.go
@@ -166,7 +166,9 @@ func (r ReplayPolicy) String() string {
 // Ack responses. Note that a nil or no payload is same as AckAck
 var (
 	// Ack
-	AckAck = []byte(OK) // nil or no payload to ack subject also means ACK
+	AckAck = []byte("+ACK") // nil or no payload to ack subject also means ACK
+	AckOK  = []byte(OK)     // deprecated but +OK meant ack as well.
+
 	// Nack
 	AckNak = []byte("-NAK")
 	// Progress indicator
@@ -595,7 +597,7 @@ func (o *Consumer) processAck(_ *subscription, _ *client, subject, reply string,
 	sseq, dseq, dcount, _ := o.ReplyInfo(subject)
 
 	switch {
-	case len(msg) == 0, bytes.Equal(msg, AckAck):
+	case len(msg) == 0, bytes.Equal(msg, AckAck), bytes.Equal(msg, AckOK):
 		o.ackMsg(sseq, dseq, dcount)
 	case bytes.Equal(msg, AckNext):
 		o.ackMsg(sseq, dseq, dcount)
diff --git a/server/stream.go b/server/stream.go
index 0b1585ee..ac698482 100644
--- a/server/stream.go
+++ b/server/stream.go
@@ -157,9 +157,9 @@ func (a *Account) AddStreamWithStore(config *StreamConfig, fsConfig *FileStoreCo
 	// Create our pubAck here. This will be reused and for +OK will contain JSON
 	// for stream name and sequence.
 	longestSeq := strconv.FormatUint(math.MaxUint64, 10)
-	lpubAck := len(AckAck) + len(cfg.Name) + len("{\"stream\": ,\"seq\": }") + len(longestSeq)
+	lpubAck := len(OK) + len(cfg.Name) + len("{\"stream\": ,\"seq\": }") + len(longestSeq)
 	mset.pubAck = make([]byte, 0, lpubAck)
-	mset.pubAck = append(mset.pubAck, AckAck...)
+	mset.pubAck = append(mset.pubAck, OK...)
 	mset.pubAck = append(mset.pubAck, fmt.Sprintf(" {\"stream\": %q, \"seq\": ", cfg.Name)...)
 
 	return mset, nil