diff --git a/.github/workflows/r2-release.yml b/.github/workflows/r2-release.yml
index 96a07685cf..6a35514cb5 100644
--- a/.github/workflows/r2-release.yml
+++ b/.github/workflows/r2-release.yml
@@ -39,6 +39,8 @@ jobs:
           AWS_SECRET_ACCESS_KEY: ${{ secrets.CODEX_R2_SECRET_ACCESS_KEY }}
           AWS_ENDPOINT_URL: ${{ vars.CODEX_R2_ENDPOINT_URL }}
           AWS_REGION: ${{ vars.CODEX_R2_REGION }}
+          AWS_RETRY_MODE: standard
+          AWS_MAX_ATTEMPTS: "6"
           GH_TOKEN: ${{ github.token }}
           RELEASE_TAG: ${{ inputs.tag }}
           RELEASE_MAKE_LATEST: ${{ inputs.make_latest }}
@@ -46,6 +48,9 @@ jobs:
           RELEASE_STAGE: ${{ inputs.stage }}
         run: |
           set -euo pipefail
+          # The publisher parallelizes objects; serialize parts within each object to avoid R2 throttling.
+          aws configure set default.s3.preferred_transfer_client classic
+          aws configure set default.s3.max_concurrent_requests 1
           python3 .github/scripts/publish_r2_release.py \
             --tag "${RELEASE_TAG}" \
             --make-latest "${RELEASE_MAKE_LATEST}" \