diff --git a/source/odm.txt b/source/odm.txt
index 2a34c4df..6a829556 100644
--- a/source/odm.txt
+++ b/source/odm.txt
@@ -1,3 +1,5 @@
+.. original URL: https://www.mongodb.com/developer/products/mongodb/mongodb-orms-odms-libraries/
+
 =========================
 ORMs, ODMs, and Libraries
 =========================