diff --git a/.github/workflows/lint_and_tests.yml b/.github/workflows/lint_and_tests.yml
index abd1599..4bf5516 100644
--- a/.github/workflows/lint_and_tests.yml
+++ b/.github/workflows/lint_and_tests.yml
@@ -5,16 +5,16 @@ on:
   push:
 
 env:
-  go-version: 1.24
+  go-version: 1.25
 
 jobs:
   unit-test:
     timeout-minutes: 20
     runs-on: ubuntu-24.04
     steps:
-      - uses: actions/checkout@v4
+      - uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6.0.1
 
-      - uses: actions/setup-go@v5
+      - uses: actions/setup-go@7a3fe6cf4cb3a834922a1244abfce67bcef6a0c5 # v6.2.0
         with:
           go-version: ${{ env.go-version }}
 
diff --git a/.golangci.yaml b/.golangci.yaml
index 5e8a3e5..38445ab 100644
--- a/.golangci.yaml
+++ b/.golangci.yaml
@@ -1,6 +1,22 @@
-run:
-  timeout: 3m
-
+version: "2"
 linters:
+  exclusions:
+    generated: lax
+    presets:
+      - comments
+      - common-false-positives
+      - legacy
+      - std-error-handling
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
+formatters:
   enable:
     - gofmt
+  exclusions:
+    generated: lax
+    paths:
+      - third_party$
+      - builtin$
+      - examples$
diff --git a/Makefile b/Makefile
index 7a9d87d..1f74f8e 100644
--- a/Makefile
+++ b/Makefile
@@ -1,8 +1,8 @@
 GIT := git
 PRE_COMMIT := pre-commit
 
-JSONNET_VERSION := v0.20.0
-GOLANGCI_VERSION := v1.64.6
+JSONNET_VERSION := v0.21.0
+GOLANGCI_VERSION := v2.8.0
 
 VERSION := v0.3.1
 
diff --git a/go.mod b/go.mod
index c4fa700..bc96a20 100644
--- a/go.mod
+++ b/go.mod
@@ -1,9 +1,9 @@
 module github.com/cybozu/pre-commit-jsonnet
 
-go 1.24
+go 1.25
 
-require golang.org/x/exp v0.0.0-20220428152302-39d4317da171
+require golang.org/x/exp v0.0.0-20260112195511-716be5621a96
 
-require github.com/sergi/go-diff v1.3.1
+require github.com/sergi/go-diff v1.4.0
 
-require golang.org/x/sys v0.31.0
+require golang.org/x/sys v0.40.0
diff --git a/go.sum b/go.sum
index 0de3ae0..3e4a855 100644
--- a/go.sum
+++ b/go.sum
@@ -6,15 +6,15 @@ github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/sergi/go-diff v1.3.1 h1:xkr+Oxo4BOQKmkn/B9eMK0g5Kg/983T9DqqPHwYqD+8=
-github.com/sergi/go-diff v1.3.1/go.mod h1:aMJSSKb2lpPvRNec0+w3fl7LP9IOFzdc9Pa4NFbPK1I=
+github.com/sergi/go-diff v1.4.0 h1:n/SP9D5ad1fORl+llWyN+D6qoUETXNZARKjyY2/KVCw=
+github.com/sergi/go-diff v1.4.0/go.mod h1:A0bzQcvG0E7Rwjx0REVgAGH58e96+X0MeOfepqsbeW4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.4.0 h1:2E4SXV/wtOkTonXsotYi4li6zVWxYlZuYNCXe9XRJyk=
 github.com/stretchr/testify v1.4.0/go.mod h1:j7eGeouHqKxXV5pUuKE4zz7dFj8WfuZ+81PSLYec5m4=
-golang.org/x/exp v0.0.0-20220428152302-39d4317da171 h1:TfdoLivD44QwvssI9Sv1xwa5DcL5XQr4au4sZ2F2NV4=
-golang.org/x/exp v0.0.0-20220428152302-39d4317da171/go.mod h1:lgLbSvA5ygNOMpwM/9anMpWVlVJ7Z+cHWq/eFuinpGE=
-golang.org/x/sys v0.31.0 h1:ioabZlmFYtWhL+TRYpcnNlLwhyxaM9kWTDEmfnprqik=
-golang.org/x/sys v0.31.0/go.mod h1:BJP2sWEmIv4KK5OTEluFJCKSidICx8ciO85XgH3Ak8k=
+golang.org/x/exp v0.0.0-20260112195511-716be5621a96 h1:Z/6YuSHTLOHfNFdb8zVZomZr7cqNgTJvA8+Qz75D8gU=
+golang.org/x/exp v0.0.0-20260112195511-716be5621a96/go.mod h1:nzimsREAkjBCIEFtHiYkrJyT+2uy9YZJB7H1k68CXZU=
+golang.org/x/sys v0.40.0 h1:DBZZqJ2Rkml6QMQsZywtnjnnGvHza6BTfYFWY9kjEWQ=
+golang.org/x/sys v0.40.0/go.mod h1:OgkHotnGiDImocRcuBABYBEXf8A9a87e/uXjp9XT3ks=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20190902080502-41f04d3bba15/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/yaml.v2 v2.2.2/go.mod h1:hI93XBmqTisBFMUTm0b8Fm+jr3Dg1NNxqwp+5A1VGuI=
diff --git a/hooks/jsonnet-fmt-hook/main.go b/hooks/jsonnet-fmt-hook/main.go
index 6a2df41..0492b20 100644
--- a/hooks/jsonnet-fmt-hook/main.go
+++ b/hooks/jsonnet-fmt-hook/main.go
@@ -99,11 +99,12 @@ func summarizeDiff(diffs []diffmatchpatch.Diff) *FileDiff {
 			endWithLineBreak = text[len(text)-1:] == "\n"
 			writeLineCount := min(maxShowLine, len(lines))
 
-			if i == 0 {
+			switch i {
+			case 0:
 				showTail = true
-			} else if i == lastDiffIdx {
+			case lastDiffIdx:
 				showHead = true
-			} else {
+			default:
 				showTail = true
 				showHead = true
 			}