diff --git a/source/index.txt b/source/index.txt
index c57f864fe2b..6903389f5ae 100644
--- a/source/index.txt
+++ b/source/index.txt
@@ -153,7 +153,7 @@ MongoDB. You can:
   <https://www.mongodb.com/lp/whitepaper/architecture-guide?tck=docs_server>`_
 
 - Read the `Practical MongoDB Aggregations
-  <https://www.practical-mongodb-aggregations.com>` e-book__
+  <https://www.practical-mongodb-aggregations.com>`__ e-book
 
 Licensing
 ---------