diff --git a/learning_python3.md b/learning_python3.md
index 6d15a2a..c43c5e8 100644
--- a/learning_python3.md
+++ b/learning_python3.md
@@ -1610,6 +1610,13 @@ What about this *super funky* gif...
 
 ![tree](./assets/tree.gif)
 
+<details>
+  <summary>Spoiler warning</summary>
+
+**Nice try... You should be able to do this on your own!**
+
+</details>
+
 # List comprehension
 
 This is a bit of an advanced topic but I'm putting it here to show you a very unique and powerful feature of python.