diff -r 40e2940605a3 -r 4bec0525ef1b src/linetypes/errorline.h
--- a/src/linetypes/errorline.h	Wed Mar 18 17:11:23 2020 +0200
+++ b/src/linetypes/errorline.h	Thu Mar 19 21:06:06 2020 +0200
@@ -9,14 +9,14 @@
 class ldraw::ErrorLine : public Object
 {
 public:
+	using BaseClass = Object;
 	ErrorLine(QStringView text = u"", QStringView message = u"");
 	QVariant getProperty(Property property) const override;
-	SetPropertyResult setProperty(
-		Property property,
-		const QVariant& value) override;
 	QString textRepresentation() const override;
 	QBrush textRepresentationForeground() const override;
 	QBrush textRepresentationBackground() const override;
 	QString text;
 	QString message;
+protected:
+	void setProperty(SetPropertyResult* result, const PropertyKeyValue& pair) override;
 };