diff --git a/docs/reference/gtk/gtk-builder-tool.xml b/docs/reference/gtk/gtk-builder-tool.xml
index f89c8e10e6..be8113bccc 100644
--- a/docs/reference/gtk/gtk-builder-tool.xml
+++ b/docs/reference/gtk/gtk-builder-tool.xml
@@ -62,6 +62,11 @@
Lists all the named objects that are created in the .ui file.
+
+ ID
+ Preview the object with the given ID. If ID is not specified,
+ try to find a suitable object to preview.
+