diff --git a/readme.txt b/readme.txt
index f110206..6a7a73c 100644
--- a/readme.txt
+++ b/readme.txt
@@ -32,6 +32,8 @@ e.g.
 
 == Changelog ==
 
+[ Specification change ] Fixed the zoom-out toggle not always displaying in the editor toolbar (updated blocks.json API version from 2 to 3).
+
 = 0.1.5 =
 [ Other ] change version only ( change WordPress.org banner ).