diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index f8b3f9e..22c2fea 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -4,26 +4,24 @@ on:
   workflow_dispatch:
     inputs:
       image_name:
-        description: "Base image name (e.g. myuser/myimage or repo/image)."
+        description: "Base image name (e.g. myuser/myimage or repo/image)"
         required: true
       tags:
         description: "Image tags (comma or space separated). Example: v1.01 latest beta"
         required: true
       dockerhub_user:
-        description: "Docker Hub username (leave empty if not pushing to Docker Hub)"
+        description: "Docker Hub username (if pushing there)"
         required: false
-      push_to_dockerhub:
-        description: "Push to Docker Hub? (true/false)"
+      registries_to_push:
+        type: choice
+        description: "Select registries to push to"
+        options:
+          - dockerhub
+          - ghcr
+          - quay
         required: false
-        default: "false"
-      push_to_ghcr:
-        description: "Push to GHCR? (true/false)"
-        required: false
-        default: "false"
-      push_to_quay:
-        description: "Push to Quay.io? (true/false)"
-        required: false
-        default: "false"
+        default: []
+        multiple: true  # allows checkbox-like UI
 
 jobs:
   build-and-push:
@@ -44,22 +42,17 @@ jobs:
           TAGS_INPUT: ${{ github.event.inputs.tags }}
           IMAGE_NAME: ${{ github.event.inputs.image_name }}
           DOCKERHUB_USER: ${{ github.event.inputs.dockerhub_user }}
-          PUSH_DOCKERHUB: ${{ github.event.inputs.push_to_dockerhub }}
-          PUSH_GHCR: ${{ github.event.inputs.push_to_ghcr }}
-          PUSH_QUAY: ${{ github.event.inputs.push_to_quay }}
+          REGISTRIES: ${{ github.event.inputs.registries_to_push }}
           GITHUB_REPOSITORY_OWNER: ${{ github.repository_owner }}
         run: |
           set -eu
-
-          # normalize commas to spaces
           TAGS_INPUT=$(echo "${TAGS_INPUT:-}" | tr ',' ' ')
 
           TAG_ARGS=""
           PRINT_LIST=""
 
           for TAG in $TAGS_INPUT; do
-            # Docker Hub
-            if [ "${PUSH_DOCKERHUB}" = "true" ]; then
+            if [[ "${REGISTRIES}" == *"dockerhub"* ]]; then
               if [ -n "${DOCKERHUB_USER}" ]; then
                 FULL_TAG="docker.io/${DOCKERHUB_USER}/${IMAGE_NAME}:$TAG"
               else
@@ -69,23 +62,19 @@ jobs:
               PRINT_LIST="${PRINT_LIST}${FULL_TAG} "
             fi
 
-            # GHCR (use repo owner namespace)
-            if [ "${PUSH_GHCR}" = "true" ]; then
+            if [[ "${REGISTRIES}" == *"ghcr"* ]]; then
               FULL_TAG="ghcr.io/${GITHUB_REPOSITORY_OWNER}/${IMAGE_NAME}:$TAG"
               TAG_ARGS="${TAG_ARGS} --tag ${FULL_TAG}"
               PRINT_LIST="${PRINT_LIST}${FULL_TAG} "
             fi
 
-            # Quay
-            if [ "${PUSH_QUAY}" = "true" ]; then
-              # If you want an org prefix for quay, include it in IMAGE_NAME when running the workflow
+            if [[ "${REGISTRIES}" == *"quay"* ]]; then
               FULL_TAG="quay.io/${IMAGE_NAME}:$TAG"
               TAG_ARGS="${TAG_ARGS} --tag ${FULL_TAG}"
               PRINT_LIST="${PRINT_LIST}${FULL_TAG} "
             fi
           done
 
-          # Export outputs for later steps
           echo "tags=${TAG_ARGS}" >> "$GITHUB_OUTPUT"
           echo "computed_tags=${PRINT_LIST}" >> "$GITHUB_OUTPUT"
 
@@ -104,18 +93,18 @@ jobs:
       - name: Fail early if no tags computed
         if: ${{ steps.tagger.outputs.computed_tags == '' }}
         run: |
-          echo "ERROR: No tags were computed for any registry. Check inputs (image_name, tags, and push_to_* flags)." >&2
+          echo "ERROR: No tags were computed for any registry. Check inputs." >&2
           exit 1
 
       - name: Log in to Docker Hub
-        if: github.event.inputs.push_to_dockerhub == 'true'
+        if: contains(github.event.inputs.registries_to_push, 'dockerhub')
         uses: docker/login-action@v3
         with:
           username: ${{ github.event.inputs.dockerhub_user }}
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Log in to GHCR
-        if: github.event.inputs.push_to_ghcr == 'true'
+        if: contains(github.event.inputs.registries_to_push, 'ghcr')
         uses: docker/login-action@v3
         with:
           registry: ghcr.io
@@ -123,7 +112,7 @@ jobs:
           password: ${{ secrets.GHCR_TOKEN }}
 
       - name: Log in to Quay.io
-        if: github.event.inputs.push_to_quay == 'true'
+        if: contains(github.event.inputs.registries_to_push, 'quay')
         uses: docker/login-action@v3
         with:
           registry: quay.io