diff --git a/.github/workflows/lint.yml b/.github/workflows/lint.yml
index e1d8d4f..04cb915 100644
--- a/.github/workflows/lint.yml
+++ b/.github/workflows/lint.yml
@@ -6,41 +6,12 @@ name: Lint
 jobs:
   golangci:
     runs-on: ubuntu-latest
-    strategy:
-      matrix:
-        go: [ '1.16' ]
     steps:
       - name: Checkout code
-        uses: actions/checkout@v2
-
-      - name: Setup go
-        uses: actions/setup-go@v2
-        with:
-          go-version: ${{ matrix.go }}
-
-      - uses: actions/cache@v2
-        with:
-          path: ~/.cache/golangci-lint
-          key: ${{ runner.os }}-golangcilint-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-golangci-lint-
-
-      - uses: actions/cache@v2
-        with:
-          path: ~/.cache/go-build
-          key: ${{ runner.os }}-gobuild-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-gobuild-
-
-      - uses: actions/cache@v2
-        with:
-          path: ~/go/pkg/mod
-          key: ${{ runner.os }}-go-${{ hashFiles('**/go.sum') }}
-          restore-keys: |
-            ${{ runner.os }}-go-
+        uses: actions/checkout@v3
 
       - name: golangci-lint
-        uses: reviewdog/action-golangci-lint@v1
+        uses: reviewdog/action-golangci-lint@v2
         with:
           reporter: github-pr-review
           filter_mode: diff_context
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d156248..229a70a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -8,7 +8,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        go: [ '1.16' ]
+        go: [ '1.18' ]
     steps:
       - name: Checkout code
         uses: actions/checkout@v2
diff --git a/go.mod b/go.mod
index b7dd104..d45da91 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/tier4/x-go
 
-go 1.17
+go 1.18
 
 require (
 	github.com/aws/aws-sdk-go v1.43.8
diff --git a/ref/ref.go b/ref/ref.go
new file mode 100644
index 0000000..fdad14b
--- /dev/null
+++ b/ref/ref.go
@@ -0,0 +1,13 @@
+package ref
+
+func Ref[T any](s T) *T {
+	return &s
+}
+
+func Deref[T any](p *T) T {
+	if p == nil {
+		var ret T
+		return ret
+	}
+	return *p
+}