--- a/ui/gtk/objs.mk	Tue Sep 08 16:08:59 2026 +0200
+++ b/ui/gtk/objs.mk	Wed Sep 09 18:57:52 2026 +0200
@@ -39,6 +39,7 @@
 GTKOBJ += display.o
 GTKOBJ += text.o
 GTKOBJ += list.o
+GTKOBJ += tree.o
 GTKOBJ += image.o
 GTKOBJ += icon.o
 GTKOBJ += graphics.o