diff --git a/server/errors.go b/server/errors.go
index 695da85..0c85f56 100644
--- a/server/errors.go
+++ b/server/errors.go
@@ -40,14 +40,16 @@ var (
 	errHTTPBadRequestAttachmentsExpiryBeforeDelivery = &errHTTP{40015, http.StatusBadRequest, "invalid request: attachment expiry before delayed delivery date", "https://ntfy.sh/docs/publish/#scheduled-delivery"}
 	errHTTPBadRequestWebSocketsUpgradeHeaderMissing  = &errHTTP{40016, http.StatusBadRequest, "invalid request: client not using the websocket protocol", "https://ntfy.sh/docs/subscribe/api/#websockets"}
 	errHTTPBadRequestJSONInvalid                     = &errHTTP{40017, http.StatusBadRequest, "invalid request: request body must be message JSON", "https://ntfy.sh/docs/publish/#publish-as-json"}
-	errHTTPNotFound                                  = &errHTTP{40401, http.StatusNotFound, "page not found", ""}
+	errHTTPNotFound                                  = &errHTTP{40401, http.StatusNotFound, "not found", ""}
+	errHTTPNotFoundMessageID                         = &errHTTP{40402, http.StatusNotFound, "not found: unable to find message with this ID", "https://ntfy.sh/docs/publish/#updating-messages"} // FIXME LINK
 	errHTTPUnauthorized                              = &errHTTP{40101, http.StatusUnauthorized, "unauthorized", "https://ntfy.sh/docs/publish/#authentication"}
 	errHTTPForbidden                                 = &errHTTP{40301, http.StatusForbidden, "forbidden", "https://ntfy.sh/docs/publish/#authentication"}
 	errHTTPTooManyRequestsLimitRequests              = &errHTTP{42901, http.StatusTooManyRequests, "limit reached: too many requests, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
 	errHTTPTooManyRequestsLimitEmails                = &errHTTP{42902, http.StatusTooManyRequests, "limit reached: too many emails, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
 	errHTTPTooManyRequestsLimitSubscriptions         = &errHTTP{42903, http.StatusTooManyRequests, "limit reached: too many active subscriptions, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
 	errHTTPTooManyRequestsLimitTotalTopics           = &errHTTP{42904, http.StatusTooManyRequests, "limit reached: the total number of topics on the server has been reached, please contact the admin", "https://ntfy.sh/docs/publish/#limitations"}
-	errHTTPTooManyRequestsAttachmentBandwidthLimit   = &errHTTP{42905, http.StatusTooManyRequests, "too many requests: daily bandwidth limit reached", "https://ntfy.sh/docs/publish/#limitations"}
+	errHTTPTooManyRequestsAttachmentBandwidthLimit   = &errHTTP{42905, http.StatusTooManyRequests, "limit reached: daily bandwidth limit reached, please be nice", "https://ntfy.sh/docs/publish/#limitations"}
+	errHTTPTooManyRequestsUpdatingTooQuickly         = &errHTTP{42906, http.StatusTooManyRequests, "limit reached: too many consecutive message updates", "https://ntfy.sh/docs/publish/#updating-messages"} // FIXME LINK
 	errHTTPInternalError                             = &errHTTP{50001, http.StatusInternalServerError, "internal server error", ""}
 	errHTTPInternalErrorInvalidFilePath              = &errHTTP{50002, http.StatusInternalServerError, "internal server error: invalid file path", ""}
 )
diff --git a/server/server.go b/server/server.go
index 0347e26..0ef6d89 100644
--- a/server/server.go
+++ b/server/server.go
@@ -395,14 +395,18 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 	if err != nil {
 		return err
 	}
-	updated := messageID != ""
 	var m *message
-	if updated {
+	update := messageID != ""
+	if update {
 		m, err = s.messageCache.Message(t.ID, messageID)
 		if err != nil {
-			return err //errors.New("message does not exist")
+			return errHTTPNotFoundMessageID
 		}
-		m.Updated = time.Now().Unix()
+		newUpdated := time.Now().Unix()
+		if newUpdated <= m.Updated {
+			return errHTTPTooManyRequestsUpdatingTooQuickly
+		}
+		m.Updated = newUpdated
 	} else {
 		m = newDefaultMessage(t.ID, "")
 	}
@@ -441,7 +445,7 @@ func (s *Server) handlePublish(w http.ResponseWriter, r *http.Request, v *visito
 		}()
 	}
 	if cache {
-		if updated {
+		if update {
 			if err := s.messageCache.UpdateMessage(m); err != nil {
 				return err
 			}
diff --git a/server/server_firebase.go b/server/server_firebase.go
index 827fec4..58d94c2 100644
--- a/server/server_firebase.go
+++ b/server/server_firebase.go
@@ -72,6 +72,7 @@ func toFirebaseMessage(m *message, auther auth.Auther) (*messaging.Message, erro
 			data = map[string]string{
 				"id":       m.ID,
 				"time":     fmt.Sprintf("%d", m.Time),
+				"updated":  fmt.Sprintf("%d", m.Updated),
 				"event":    m.Event,
 				"topic":    m.Topic,
 				"priority": fmt.Sprintf("%d", m.Priority),
diff --git a/server/types.go b/server/types.go
index d003df2..0ab357f 100644
--- a/server/types.go
+++ b/server/types.go
@@ -20,9 +20,11 @@ const (
 
 // message represents a message published to a topic
 type message struct {
-	ID         string      `json:"id"`    // Random message ID
-	Time       int64       `json:"time"`  // Unix time in seconds
-	Event      string      `json:"event"` // One of the above
+	ID         string      `json:"id"`                // Random message ID
+	Time       int64       `json:"time"`              // Unix time in seconds
+	Updated    int64       `json:"updated,omitempty"` // Set if updated, unix time in seconds
+	Deleted    int64       `json:"deleted,omitempty"` // Set if deleted, unix time in seconds
+	Event      string      `json:"event"`             // One of the above
 	Topic      string      `json:"topic"`
 	Priority   int         `json:"priority,omitempty"`
 	Tags       []string    `json:"tags,omitempty"`
@@ -31,8 +33,6 @@ type message struct {
 	Title      string      `json:"title,omitempty"`
 	Message    string      `json:"message,omitempty"`
 	Encoding   string      `json:"encoding,omitempty"` // Empty for raw UTF-8, or "base64" for encoded bytes
-	Updated    int64       `json:"updated,omitempty"`  // Set if updated, unix time in seconds
-	Deleted    int64       `json:"deleted,omitempty"`  // Set if deleted, unix time in seconds
 }
 
 type attachment struct {