diff --git a/.github/workflows/lint-test.yaml b/.github/workflows/lint-test.yaml
index a47d56d..4bbeca5 100644
--- a/.github/workflows/lint-test.yaml
+++ b/.github/workflows/lint-test.yaml
@@ -7,7 +7,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - name: Checkout
-        uses: actions/checkout@v2
+        uses: actions/checkout@v4
         with:
           fetch-depth: 0
 
@@ -16,12 +16,12 @@ jobs:
         with:
           version: v3.4.0
 
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v5
         with:
-          python-version: 3.7
+          python-version: 3.9
 
       - name: Set up chart-testing
-        uses: helm/chart-testing-action@v2.1.0
+        uses: helm/chart-testing-action@v2.7.0
 
       - name: Run chart-testing (list-changed)
         id: list-changed
diff --git a/Dockerfile b/Dockerfile
index beb5a94..70f0c64 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -12,8 +12,8 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-ARG ALPINE_VERSION=3.20
-ARG GO_VERSION=1.23
+ARG ALPINE_VERSION=3.21
+ARG GO_VERSION=1.24
 ARG PLATFORM=linux/amd64
 ###
 ### Build PGPool-II from source in a build container
@@ -58,7 +58,7 @@ RUN make DESTDIR=/pgpool_bin install
 ###
 ### build envtpl
 ###
-FROM --platform=${PLATFORM} golang:$GO_VERSION-alpine AS go_build
+FROM --platform=${PLATFORM} golang:$GO_VERSION-alpine${ALPINE_VERSION} AS go_build
 RUN apk update
 RUN apk add --no-cache git make build-base python3 curl
 WORKDIR /src
diff --git a/README.md b/README.md
index ad66685..500fa22 100644
--- a/README.md
+++ b/README.md
@@ -50,6 +50,7 @@ instance no matter what.  This is configureable at deploy time as
 
 Old Version | New Version | Upgrade Guide
 --- | --- | ---
+v1.3.2 | v1.3.3 | [link](UPGRADE.md#v132--v13r)
 v1.3.1 | v1.3.2 | [link](UPGRADE.md#v131--v132)
 v1.3.0 | v1.3.1 | [link](UPGRADE.md#v130--v131)
 v1.2.0 | v1.3.0 | [link](UPGRADE.md#v120--v130)
@@ -80,7 +81,7 @@ helm repo update
 ```sh
 export RELEASE_NAME=my-pgpool-service # a name (you will need 1 installed chart for each primary DB)
 export NAMESPACE=my-k8s-namespace     # a kubernetes namespace
-export CHART_VERSION=1.3.2            # a chart version: https://github.com/odenio/pgpool-cloudsql/releases
+export CHART_VERSION=1.3.3            # a chart version: https://github.com/odenio/pgpool-cloudsql/releases
 export VALUES_FILE=./my_values.yaml   # your values file
 
 helm install \
@@ -122,7 +123,7 @@ Parameter | Description | Default
 --- | --- | ---
 `deploy.replicaCount` | Number of pod replicas to deploy | `1`
 `deploy.repository` | Docker image repository of the runtime container image | `odentech/pgpool-cloudsql`
-`deploy.tag` | If set, override the tag of the runtime container image. If left empty, we use the concatenation of the chart version (`1.2.0`) and the selected `pgpool.version` e.g. `1.3.2-4.5.4` | `""`
+`deploy.tag` | If set, override the tag of the runtime container image. If left empty, we use the concatenation of the chart version (`1.2.0`) and the selected `pgpool.version` e.g. `1.3.3-4.5.4` | `""`
 `deploy.service.tier` | Value for the "tier" [label](https://kubernetes.io/docs/concepts/overview/working-with-objects/labels/) applied to the kubernetes [service](https://kubernetes.io/docs/concepts/services-networking/service/) | `db`
 `deploy.service.additionalLabels` | Map of additional k/v string pairs to add as labels for the kubernetes service | `{}`
 `deploy.annotations` | Kubernetes [annotation](https://kubernetes.io/docs/concepts/overview/working-with-objects/annotations/) spec applied to the deployment pods | `{}`
diff --git a/UPGRADE.md b/UPGRADE.md
index 0fded07..18a69df 100644
--- a/UPGRADE.md
+++ b/UPGRADE.md
@@ -1,5 +1,12 @@
 # Upgrading Steps
 
+## `v1.3.2` → `v1.3.3`
+
+This is a maintenance release:
+
+* the version of the Go runtime used to build the envtpl package is bumped from 1.23 to 1.24
+* the Alpine Linux base image is updated from v3.20 to v3.21
+
 ## `v1.3.1` → `v1.3.2`
 
 This is a maintenance release:
diff --git a/charts/pgpool-cloudsql/Chart.yaml b/charts/pgpool-cloudsql/Chart.yaml
index cb9f638..fc67709 100644
--- a/charts/pgpool-cloudsql/Chart.yaml
+++ b/charts/pgpool-cloudsql/Chart.yaml
@@ -15,7 +15,7 @@ apiVersion: v2
 description: the pgpool-ii connection pooling postgres proxy with automatic discovery of GCP CloudSQL backends
 name: pgpool-cloudsql
 type: application
-version: 1.3.2
+version: 1.3.3
 keywords:
 - postgresql
 - pgpool