diff --git a/Documentation/git-multi-pack-index.txt b/Documentation/git-multi-pack-index.txt
index b4a2378cd8..11e6dc53e3 100644
--- a/Documentation/git-multi-pack-index.txt
+++ b/Documentation/git-multi-pack-index.txt
@@ -71,8 +71,9 @@ verify::
 
 expire::
 	Delete the pack-files that are tracked by the MIDX file, but
-	have no objects referenced by the MIDX. Rewrite the MIDX file
-	afterward to remove all references to these pack-files.
+	have no objects referenced by the MIDX (with the exception of
+	`.keep` packs). Rewrite the MIDX file afterward to remove all
+	references to these pack-files.
 
 repack::
 	Create a new pack-file containing objects in small pack-files