diff --git a/README.md b/README.md
index d459953..e197356 100644
--- a/README.md
+++ b/README.md
@@ -197,39 +197,35 @@ func run() errs.Err {
 
 ## Supporting Go versions
 
-This framework supports Go 1.21 or later.
+This framework supports Go 1.23 or later.
 
 ### Actual test results for each Go version:
 
 ```sh
 % gvm-fav
-Now using version go1.21.13
-go version go1.21.13 darwin/amd64
-ok  	github.com/sttk/sabi	8.916s	coverage: 96.9% of statements
+Now using version go1.23.12
+go version go1.23.12 darwin/amd64
+ok  	github.com/sttk/sabi	8.564s	coverage: 97.0% of statements
 
-Now using version go1.22.12
-go version go1.22.12 darwin/amd64
-ok  	github.com/sttk/sabi	8.912s	coverage: 96.9% of statements
+Now using version go1.24.13
+go version go1.24.13 darwin/amd64
+ok  	github.com/sttk/sabi	8.572s	coverage: 97.0% of statements
 
-Now using version go1.23.10
-go version go1.23.10 darwin/amd64
-ok  	github.com/sttk/sabi	8.919s	coverage: 96.9% of statements
+Now using version go1.25.8
+go version go1.25.8 darwin/amd64
+ok  	github.com/sttk/sabi	8.778s	coverage: 97.0% of statements
 
-Now using version go1.24.6
-go version go1.24.6 darwin/amd64
-ok  	github.com/sttk/sabi	8.930s	coverage: 96.9% of statements
+Now using version go1.26.1
+go version go1.26.1 darwin/amd64
+ok  	github.com/sttk/sabi	8.739s	coverage: 97.0% of statements
 
-Now using version go1.25.0
-go version go1.25.0 darwin/amd64
-ok  	github.com/sttk/sabi	8.923s	coverage: 96.9% of statements
-
-Back to go1.25.0
-Now using version go1.25.0
+Back to go1.26.1
+Now using version go1.26.1
 ```
 
 ## License
 
-Copyright (C) 2022-2025 Takayuki Sato
+Copyright (C) 2022-2026 Takayuki Sato
 
 This program is free software under MIT License.<br>
 See the file LICENSE in this distribution for more details.
diff --git a/data-acc.go b/data-acc.go
index 1b4c834..97651ff 100644
--- a/data-acc.go
+++ b/data-acc.go
@@ -1,4 +1,4 @@
-// Copyright (C) 2023-2025 Takayuki Sato. All Rights Reserved.
+// Copyright (C) 2023-2026 Takayuki Sato. All Rights Reserved.
 // This program is free software under MIT License.
 // See the file LICENSE in this distribution for more details.
 
diff --git a/data-hub.go b/data-hub.go
index ce0a664..69b0612 100644
--- a/data-hub.go
+++ b/data-hub.go
@@ -1,4 +1,4 @@
-// Copyright (C) 2023-2025 Takayuki Sato. All Rights Reserved.
+// Copyright (C) 2023-2026 Takayuki Sato. All Rights Reserved.
 // This program is free software under MIT License.
 // See the file LICENSE in this distribution for more details.
 
diff --git a/doc.go b/doc.go
index 0fb4294..2437503 100644
--- a/doc.go
+++ b/doc.go
@@ -1,4 +1,4 @@
-// Copyright (C) 2023-2025 Takayuki Sato. All Rights Reserved.
+// Copyright (C) 2023-2026 Takayuki Sato. All Rights Reserved.
 // This program is free software under MIT License.
 // See the file LICENSE in this distribution for more details.
 
diff --git a/go.mod b/go.mod
index 0df983e..b737bcc 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/sttk/sabi
 
-go 1.21
+go 1.23
 
 require (
 	github.com/stretchr/testify v1.10.0