diff --git a/_quarto.yml b/_quarto.yml
index a9e082f..fb4eb2a 100644
--- a/_quarto.yml
+++ b/_quarto.yml
@@ -17,6 +17,8 @@ book:
     - index.qmd
     - 001-toc.qmd
     - part: R Language
+      chapters: 
+        - 002-obj.qmd
     - part: R Basics
     - part: R Programming
     - part: R Output