diff --git a/book/_toc.yml b/book/_toc.yml
index c3263ab..e93a13f 100644
--- a/book/_toc.yml
+++ b/book/_toc.yml
@@ -16,6 +16,7 @@ parts:
       - file: exercises/005.md
       - file: exercises/005a.md
       - file: exercises/006.md
+      - file: exercises/007.md
       - file: exercises/summary
     - file: syntax_exercises.md
       sections: