diff --git a/.github/workflows/go.yml b/.github/workflows/go.yml
index 4e8b917d..647c692f 100644
--- a/.github/workflows/go.yml
+++ b/.github/workflows/go.yml
@@ -10,7 +10,7 @@ jobs:
     strategy:
       matrix:
         os: [ "ubuntu-latest", "macos-latest", "windows-latest" ]
-        go-version: [ "1.18", "1.19", "1.20" ]
+        go-version: [ "1.19", "1.20", "1.21" ]
     runs-on: ${{ matrix.os }}
     steps:
     - name: checkout
@@ -28,7 +28,7 @@ jobs:
     strategy:
       matrix:
         os: [ "ubuntu-latest", "windows-latest" ]
-        go-version: [ "1.18", "1.19", "1.20" ]
+        go-version: [ "1.19", "1.20", "1.21" ]
     runs-on: ${{ matrix.os }}
     env:
       GOARCH: "386"
@@ -52,7 +52,7 @@ jobs:
       - name: setup Go
         uses: actions/setup-go@v4
         with:
-          go-version: "1.20"
+          go-version: "1.21"
       - name: build
         run: |
           make ycat/build
@@ -69,7 +69,7 @@ jobs:
       - name: setup Go
         uses: actions/setup-go@v4
         with:
-          go-version: "1.20"
+          go-version: "1.21"
       - name: measure coverage
         run: |
           make cover
diff --git a/go.mod b/go.mod
index f6e74c30..4550ff37 100644
--- a/go.mod
+++ b/go.mod
@@ -1,6 +1,6 @@
 module github.com/goccy/go-yaml
 
-go 1.18
+go 1.19
 
 require (
 	github.com/fatih/color v1.10.0