diff --git a/CHANGELOG.md b/CHANGELOG.md
index 46b075999..4ae64627e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -3,3 +3,5 @@ v0.21 + 1
 
 * File unlocks are atomic again via rename. Read-only files on Windows are
   made read-write if necessary.
+
+* Share open packfiles across repositories to share descriptors and mmaps.