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 ).
 
diff --git a/src/copy-button-wrap/block.json b/src/copy-button-wrap/block.json
index b3a59a4..ab82685 100644
--- a/src/copy-button-wrap/block.json
+++ b/src/copy-button-wrap/block.json
@@ -1,5 +1,5 @@
 {
-	"apiVersion": 2,
+	"apiVersion": 3,
 	"name": "vk-simple-copy-block/copy-button-wrap",
 	"category": "vk-simple-copy-block",
 	"title": "Copy Button",
diff --git a/src/copy-button/block.json b/src/copy-button/block.json
index 9d879f3..41d324c 100644
--- a/src/copy-button/block.json
+++ b/src/copy-button/block.json
@@ -1,5 +1,5 @@
 {
-	"apiVersion": 2,
+	"apiVersion": 3,
 	"name": "vk-simple-copy-block/copy-button",
 	"category": "vk-simple-copy-block",
 	"title": "Copy Button",
diff --git a/src/copy-target/block.json b/src/copy-target/block.json
index 5bd3ea7..d49d111 100644
--- a/src/copy-target/block.json
+++ b/src/copy-target/block.json
@@ -1,5 +1,5 @@
 {
-	"apiVersion": 2,
+	"apiVersion": 3,
 	"name": "vk-simple-copy-block/copy-target",
 	"category": "vk-simple-copy-block",
 	"title": "Copy Target",
diff --git a/src/simple-copy/block.json b/src/simple-copy/block.json
index cfeaf74..b69c2be 100644
--- a/src/simple-copy/block.json
+++ b/src/simple-copy/block.json
@@ -1,5 +1,5 @@
 {
-	"apiVersion": 2,
+	"apiVersion": 3,
 	"name": "vk-simple-copy-block/simple-copy",
 	"category": "vk-simple-copy-block",
 	"title": "Simple Copy",