diff --git a/.github/workflows/ruby.yml b/.github/workflows/ruby.yml
index cb22c31..0578133 100644
--- a/.github/workflows/ruby.yml
+++ b/.github/workflows/ruby.yml
@@ -11,6 +11,11 @@ on:
       - ruby/Dockerfile
       - .github/workflows/ruby.yml
   workflow_dispatch:
+    inputs:
+      force:
+        description: Rebuild all images
+        type: boolean
+        default: false
 
 env:
   REGISTRY: ghcr.io
@@ -37,14 +42,38 @@ jobs:
 
       - uses: docker/setup-buildx-action@v4
 
+      - name: Check if Dockerfile changed
+        id: dockerfile
+        run: |
+          if [ "${{ github.event_name }}" = "pull_request" ]; then
+            BASE="${{ github.event.pull_request.base.sha }}"
+          else
+            BASE="${{ github.event.before }}"
+          fi
+          if git diff --name-only "$BASE" "${{ github.sha }}" -- ruby/Dockerfile | grep -q .; then
+            echo "changed=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "changed=false" >> "$GITHUB_OUTPUT"
+          fi
+
+      - name: Check if image exists
+        id: check
+        run: |
+          if docker buildx imagetools inspect "${{ env.REGISTRY }}/${{ env.IMAGE_NAME }}:${{ matrix.ruby-version }}" >/dev/null 2>&1; then
+            echo "exists=true" >> "$GITHUB_OUTPUT"
+          else
+            echo "exists=false" >> "$GITHUB_OUTPUT"
+          fi
+
       - uses: docker/login-action@v4
-        if: github.event_name != 'pull_request'
+        if: github.event_name != 'pull_request' && (steps.check.outputs.exists != 'true' || steps.dockerfile.outputs.changed == 'true' || (github.event_name == 'workflow_dispatch' && inputs.force))
         with:
           registry: ${{ env.REGISTRY }}
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
 
       - uses: docker/build-push-action@v7
+        if: steps.check.outputs.exists != 'true' || steps.dockerfile.outputs.changed == 'true' || (github.event_name == 'workflow_dispatch' && inputs.force)
         with:
           context: ruby
           platforms: linux/amd64,linux/arm64