diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index 3e83956..1661cd9 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -4,7 +4,7 @@ on:
   push:
     branches: [ main ]
     tags: [ 'v*' ]
-  pull_request:
+  pull_request: # if also at push, add "type=ref,event=branch" to docker meta
 
 env:
   JAVA_VERSION: 15
@@ -14,6 +14,10 @@ jobs:
   lint:
     runs-on: ubuntu-latest
 
+    strategy:
+      matrix:
+        system: [ checkstyle, spotbugs, pmd ]
+
     steps:
       - uses: actions/checkout@v2
 
@@ -35,23 +39,26 @@ jobs:
         run: chmod +x gradlew
 
       - name: Lint with Gradle
-        run: ./gradlew checkstyleMain checkstyleTest spotbugsMain spotbugsTest pmdMain pmdTest --stacktrace --no-daemon --refresh-dependencies
+        run: ./gradlew ${{ matrix.system }}Main ${{ matrix.system }}Test --stacktrace --no-daemon --refresh-dependencies
 
-      - name: Annotate Checkstyle Issues
+      - name: Annotate checkstyle violations
+        if: matrix.system == 'checkstyle'
         uses: jwgmeligmeyling/checkstyle-github-action@master
         with:
           path: '**/build/reports/checkstyle/*.xml'
 
-      - name: Annotate SpotBugs Issues
-        uses: jwgmeligmeyling/spotbugs-github-action@master
-        with:
-          path: '**/build/reports/spotbugs/*.xml'
-
-      - name: Annotate PMD Issues
+      - name: Annotate pmd violations
+        if: matrix.system == 'pmd'
         uses: jwgmeligmeyling/pmd-github-action@master
         with:
           path: '**/build/reports/pmd/*.xml'
 
+      - name: Annotate spotbugs violations
+        if: matrix.system == 'spotbugs'
+        uses: jwgmeligmeyling/spotbugs-github-action@master
+        with:
+          path: '**/build/reports/spotbugs/*.xml'
+
   nohttp:
     runs-on: ubuntu-latest
 
@@ -166,11 +173,10 @@ jobs:
           tags: |
             type=edge
             type=ref,event=pr
-            type=ref,event=branch
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}
           flavor: |
-            prefix=${{ matrix.jvm-impl }}
+            suffix=-${{ matrix.jvm-impl }}
             latest=${{ matrix.jvm-impl == 'hotspot' }}
 
       - uses: docker/setup-qemu-action@v1
@@ -186,14 +192,14 @@ jobs:
 
       - name: Login to Docker Hub
         uses: docker/login-action@v1
-        if: ${{ github.event_name != 'pull_request' }}
+        if: github.event_name != 'pull_request'
         with:
           username: ${{ secrets.DOCKER_USERNAME }}
           password: ${{ secrets.DOCKER_TOKEN }}
 
       - name: Login to GitHub Container Registry
         uses: docker/login-action@v1
-        if: ${{ github.event_name != 'pull_request' }}
+        if: github.event_name != 'pull_request'
         with:
           registry: ghcr.io
           username: ${{ github.repository_owner }}
@@ -223,8 +229,14 @@ jobs:
           rm -rf /tmp/.buildx-cache
           mv /tmp/.buildx-cache-new /tmp/.buildx-cache
 
+      - name: Inspect image
+        if: github.event_name != 'pull_request'
+        run: |
+          docker pull ${{ env.IMAGE_NAME }}:${{ steps.docker_meta.outputs.version }}
+          docker image inspect ${{ env.IMAGE_NAME }}:${{ steps.docker_meta.outputs.version }}
+
       - name: Check manifest
-        if: ${{ github.event_name != 'pull_request' }}
+        if: github.event_name != 'pull_request'
         run: |
           docker buildx imagetools inspect ${{ env.IMAGE_NAME }}:${{ steps.docker_meta.outputs.version }}
           docker buildx imagetools inspect ghcr.io/${{ env.IMAGE_NAME }}:${{ steps.docker_meta.outputs.version }}