diff --git a/appservice/http.go b/appservice/http.go
index 6aebef10..a478d3ec 100644
--- a/appservice/http.go
+++ b/appservice/http.go
@@ -192,7 +192,7 @@ func (as *AppService) handleEvents(evts []*event.Event, defaultTypeClass event.T
 			evt.Type.Class = event.MessageEventType
 		}
 		err := evt.Content.ParseRaw(evt.Type)
-		if errors.Is(err, event.UnsupportedContentType) {
+		if errors.Is(err, event.ErrUnsupportedContentType) {
 			as.Log.Debugfln("Not parsing content of %s: %v", evt.ID, err)
 		} else if err != nil {
 			as.Log.Debugfln("Failed to parse content of %s (type %s): %v", evt.ID, evt.Type.Type, err)
diff --git a/event/content.go b/event/content.go
index 78a0867e..39d466de 100644
--- a/event/content.go
+++ b/event/content.go
@@ -150,19 +150,19 @@ func (content *Content) MarshalJSON() ([]byte, error) {
 }
 
 func IsUnsupportedContentType(err error) bool {
-	return errors.Is(err, UnsupportedContentType)
+	return errors.Is(err, ErrUnsupportedContentType)
 }
 
-var ContentAlreadyParsed = errors.New("content is already parsed")
-var UnsupportedContentType = errors.New("unsupported event type")
+var ErrContentAlreadyParsed = errors.New("content is already parsed")
+var ErrUnsupportedContentType = errors.New("unsupported event type")
 
 func (content *Content) ParseRaw(evtType Type) error {
 	if content.Parsed != nil {
-		return ContentAlreadyParsed
+		return ErrContentAlreadyParsed
 	}
 	structType, ok := TypeMap[evtType]
 	if !ok {
-		return fmt.Errorf("%w %s", UnsupportedContentType, evtType.Repr())
+		return fmt.Errorf("%w %s", ErrUnsupportedContentType, evtType.Repr())
 	}
 	content.Parsed = reflect.New(structType).Interface()
 	return json.Unmarshal(content.VeryRaw, &content.Parsed)