diff --git a/src/SUMMARY.md b/src/SUMMARY.md
index 567bcf0..ff51d94 100644
--- a/src/SUMMARY.md
+++ b/src/SUMMARY.md
@@ -47,5 +47,6 @@
   - [What is Distributed Computing](./chapter5/distributed-computing.md)
   - [Message Passing](./chapter5/message-passing.md)
   - [OpenMPI](./chapter5/openmpi.md)
+  - [Challenges](./chapter5/challenges.md)
 
 [Acknowledgements](./acknowledgements.md)