diff --git a/structs.go b/structs.go
index f6aad1c..78a9993 100644
--- a/structs.go
+++ b/structs.go
@@ -78,14 +78,18 @@ type Message struct {
 }
 
 type Group struct {
-	Name             string              `json:"name"`
-	CreatedAt        time.Time           `json:"createdAt"`
-	Id               uint32              `json:"-"`
-	CreatorId        uint32              `json:"creatorId"`
-	OwnerId          uint32              `json:"ownerId"`
-	Users            map[uint32]struct{} `json:"-"`
-	Color            [3]uint8            `json:"color"`
-	EnableUserColors bool                `json:"enableUserColors"`
+	Mu                        sync.RWMutex                `json:"-"`
+	Name                      string                      `json:"name"`
+	CreatedAt                 time.Time                   `json:"createdAt"`
+	MessagesBuff              [MaxDirectMsgCache]*Message `json:"-"`
+	NextBuffIdx               uint32                      `json:"-"`
+	Id                        uint32                      `json:"-"`
+	CreatorId                 uint32                      `json:"creatorId"`
+	OwnerId                   uint32                      `json:"ownerId"`
+	Users                     map[uint32]struct{}         `json:"-"`
+	Color                     [3]uint8                    `json:"color"`
+	EnableUserColors          bool                        `json:"enableUserColors"`
+	HaveMessageBuffOverflowed bool                        `json:"-"`
 }
 
 type LoginReturn struct {