diff --git a/websocket_managed_conn.go b/websocket_managed_conn.go
index dbbf682df..9eaaa6644 100644
--- a/websocket_managed_conn.go
+++ b/websocket_managed_conn.go
@@ -577,5 +577,6 @@ var EventMapping = map[string]interface{}{
 	"subteam_self_removed": SubteamSelfRemovedEvent{},
 	"subteam_updated":      SubteamUpdatedEvent{},
 
-	"desktop_notification": DesktopNotificationEvent{},
+	"desktop_notification":       DesktopNotificationEvent{},
+	"mobile_in_app_notification": MobileInAppNotificationEvent{},
 }
diff --git a/websocket_mobile_in_app_notification.go b/websocket_mobile_in_app_notification.go
new file mode 100644
index 000000000..e3cfb3d9f
--- /dev/null
+++ b/websocket_mobile_in_app_notification.go
@@ -0,0 +1,20 @@
+package slack
+
+// MobileInAppNotificationEvent represents the update event for Mobile App Notification.
+type MobileInAppNotificationEvent struct {
+	Type              string `json:"type"`
+	Title             string `json:"title"`
+	Subtitle          string `json:"subtitle"`
+	Timestamp         string `json:"ts"`
+	Channel           string `json:"channel"`
+	AvatarImage       string `json:"avatarImage"`
+	IsShared          bool   `json:"is_shared"`
+	ChannelName       string `json:"channel_name"`
+	AuthorID          string `json:"author_id"`
+	AuthorDisplayName string `json:"author_display_name"`
+	MessageText       string `json:"msg_text"`
+	PushID            string `json:"push_id"`
+	NotifcationID     string `json:"notif_id"`
+	MobileLaunchURI   string `json:"mobileLaunchUri"`
+	EventTimestamp    string `json:"event_ts"`
+}