diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index fc06009..5fc022a 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -11,7 +11,9 @@ env:
 
 "on":
   merge_group: {}
-  pull_request: {}
+  pull_request:
+    branches:
+      - main
   push:
     branches-ignore:
       # These should always correspond to pull requests, so ignore them for
@@ -78,11 +80,13 @@ jobs:
         with:
           fetch-depth: 0
 
-      - uses: lsst-sqre/build-and-push-to-ghcr@v1
+      - uses: lsst-sqre/build-and-push-to-ghcr@u/tobyj/docker_target
         id: build
         with:
           image: ${{ github.repository }}
+          target: runtime-image
           github_token: ${{ secrets.GITHUB_TOKEN }}
+          push: false
 
   # Release -- when PR is merged to main, bump version, make tag, recommit
   release: