diff --git a/.github/workflows/_docker-image.yml b/.github/workflows/_docker-image.yml
index 701f9432fc0..a328a8fc3ca 100644
--- a/.github/workflows/_docker-image.yml
+++ b/.github/workflows/_docker-image.yml
@@ -3,7 +3,7 @@ name: Resolve CI docker image
 # linux_job_v3 passes `docker-image` straight to the runner pod's container, which
 # is pulled before any step runs, so nothing inside the job can derive it. Callers
 # depend on this workflow and name the image as
-# 308535385114.dkr.ecr.us-east-1.amazonaws.com/executorch/ci-image:<name>-<hash>.
+# ${docker-registry}/ci-image:<name>-${ci-docker-hash}.
 #
 # Nothing here waits for docker-builds. A commit that changes .ci/docker needs the
 # ciflow/docker label to build the images it asks for; without them the pod fails
@@ -15,6 +15,12 @@ on:
       ci-docker-hash:
         description: Tag suffix shared by every executorch CI image for this commit.
         value: ${{ jobs.resolve.outputs.ci-docker-hash }}
+      docker-registry:
+        description: |
+          Registry and namespace the CI images live in. An output rather than a
+          literal at each call site, and not an `env`, which GitHub does not
+          allow in a reusable workflow's `with`.
+        value: 308535385114.dkr.ecr.us-east-1.amazonaws.com/executorch
 
 permissions:
   contents: read
diff --git a/.github/workflows/_unittest.yml b/.github/workflows/_unittest.yml
index 4216d3aaa27..2b702b1ac1f 100644
--- a/.github/workflows/_unittest.yml
+++ b/.github/workflows/_unittest.yml
@@ -30,14 +30,19 @@ on:
         default: 90
 
 jobs:
+  docker-image:
+    name: Resolve CI docker image
+    uses: ./.github/workflows/_docker-image.yml
+
   linux:
-    uses: pytorch/test-infra/.github/workflows/linux_job_v2.yml@main
+    needs: docker-image
+    uses: pytorch/test-infra/.github/workflows/linux_job_v3.yml@main
     permissions:
       id-token: write
       contents: read
     with:
-      runner: linux.2xlarge.memory
-      docker-image: ${{ inputs.docker-image }}
+      runner: mt-l-x86iavx512-8-64
+      docker-image: ${{ needs.docker-image.outputs.docker-registry }}/${{ inputs.docker-image }}-${{ needs.docker-image.outputs.ci-docker-hash }}
       submodules: 'recursive'
       ref: ${{ github.event_name == 'pull_request' && github.event.pull_request.head.sha || github.sha }}
       timeout: ${{ inputs.linux-timeout }}