diff --git a/.github/workflows/linux-builder-update.yml b/.github/workflows/linux-builder-update.yml
index 18b4c47..c2b8827 100644
--- a/.github/workflows/linux-builder-update.yml
+++ b/.github/workflows/linux-builder-update.yml
@@ -13,7 +13,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
@@ -40,7 +40,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
@@ -67,7 +67,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
@@ -94,7 +94,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
@@ -121,7 +121,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
@@ -148,7 +148,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
@@ -175,7 +175,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
@@ -202,7 +202,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
diff --git a/.github/workflows/pr.yml b/.github/workflows/pr.yml
index 9d94a92..f17dce4 100644
--- a/.github/workflows/pr.yml
+++ b/.github/workflows/pr.yml
@@ -2,7 +2,22 @@ name: PR
 
 on: pull_request
 
+concurrency:
+  group: ${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
+  actionlint:
+    name: Lint GitHub Action Workflows
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Check workflow files
+        uses: docker://ponylang/shared-docker-ci-actionlint:20230810
+        with:
+          args: -color
+
   superlinter:
     name: Lint bash, docker, markdown, and yaml
     runs-on: ubuntu-latest
@@ -18,6 +33,14 @@ jobs:
           VALIDATE_MD: true
           VALIDATE_YAML: true
 
+  validate-actionlint-image-builds:
+    name: Validate release Docker image builds
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: Docker build
+        run: "docker build --pull --file=actionlint/Dockerfile ."
+
   validate-release-a-library-image-builds:
     name: Validate release-a-library Docker image builds
     runs-on: ubuntu-latest
diff --git a/.github/workflows/release-a-library-update.yml b/.github/workflows/release-a-library-update.yml
index 14f2a7c..3e65037 100644
--- a/.github/workflows/release-a-library-update.yml
+++ b/.github/workflows/release-a-library-update.yml
@@ -14,7 +14,7 @@ jobs:
     steps:
       - uses: actions/checkout@v2
       - name: Docker login
-        run: "docker login -u $DOCKER_USERNAME -p $DOCKER_PASSWORD"
+        run: docker login -u "$DOCKER_USERNAME" -p "$DOCKER_PASSWORD"
         env:
           DOCKER_PASSWORD: ${{ secrets.DOCKER_PASSWORD }}
           DOCKER_USERNAME: ${{ secrets.DOCKER_USERNAME }}
diff --git a/actionlint/Dockerfile b/actionlint/Dockerfile
new file mode 100644
index 0000000..e002531
--- /dev/null
+++ b/actionlint/Dockerfile
@@ -0,0 +1,15 @@
+FROM alpine:3.18
+
+RUN apk add --update --no-cache \
+  bash \
+  py3-pyflakes \
+  shellcheck
+
+RUN cd /tmp && \
+  wget https://github.com/rhysd/actionlint/releases/download/v1.6.25/actionlint_1.6.25_linux_386.tar.gz && \
+  tar xf actionlint_1.6.25_linux_386.tar.gz && \
+  cp actionlint /usr/bin/ && \
+  chmod a+x /usr/bin/actionlint && \
+  rm -rf /tmp/*
+
+ ENTRYPOINT ["/usr/bin/actionlint"]
diff --git a/actionlint/build-and-push.bash b/actionlint/build-and-push.bash
new file mode 100644
index 0000000..7751fa5
--- /dev/null
+++ b/actionlint/build-and-push.bash
@@ -0,0 +1,15 @@
+#!/bin/bash
+
+set -o errexit
+set -o nounset
+
+#
+# *** You should already be logged in to DockerHub when you run this ***
+#
+
+NAME="ponylang/shared-docker-ci-actionlint"
+TODAY=$(date +%Y%m%d)
+DOCKERFILE_DIR="$(dirname "$0")"
+
+docker build --pull -t "${NAME}:${TODAY}" "${DOCKERFILE_DIR}"
+docker push "${NAME}:${TODAY}"