diff --git a/source/includes/copy-existing-admonition.rst b/source/includes/copy-existing-admonition.rst
index 1c51d141..537923f7 100644
--- a/source/includes/copy-existing-admonition.rst
+++ b/source/includes/copy-existing-admonition.rst
@@ -2,4 +2,5 @@ If any system changes the data in the database while the source connector
 converts existing data from it, MongoDB may produce duplicate change
 stream events to reflect the latest changes.  Since the change stream
 events on which the data copy relies are idempotent, the copied data is
-eventually consistent.
+eventually consistent. This is why the source connector's delivery 
+guarantee is "at-least-once".