diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 81e6c491..2d6f22c7 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -21,14 +21,75 @@ jobs:
       - uses: actions/checkout@v6
         with:
           path: cle
+      - name: Resolve the angr/binaries ref
+        id: binaries-ref
+        shell: bash
+        env:
+          GH_TOKEN: ${{ github.token }}
+          PR_BODY: ${{ github.event.pull_request.body }}
+        run: |
+          ref=master
+          number=$(printf '%s' "$PR_BODY" |
+            grep -Eo '(angr/binaries#|github\.com/angr/binaries/pull/)[0-9]+' |
+            head -n 1 |
+            grep -Eo '[0-9]+$') || true
+          if [ -n "$number" ]; then
+            state=$(gh api "repos/angr/binaries/pulls/$number" --jq .state) || state=unavailable
+            if [ "$state" = open ]; then
+              ref="refs/pull/$number/head"
+            else
+              echo "angr/binaries#$number is $state, so it is not used"
+            fi
+          fi
+          echo "Checking out angr/binaries at $ref"
+          echo "ref=$ref" >>"$GITHUB_OUTPUT"
       - uses: actions/checkout@v6
         with:
           repository: angr/binaries
           path: binaries
+          ref: ${{ steps.binaries-ref.outputs.ref }}
       - name: Install the latest version of uv
         uses: astral-sh/setup-uv@08807647e7069bb48b6ef5acd8ec9567f424441b # v8.1.0
       - uses: ilammy/msvc-dev-cmd@0b201ec74fa43914dc39ae48a89fd1d8cb592756 # v1
         if: runner.os == 'Windows'
+      - name: Resolve referenced sibling pull requests
+        working-directory: cle
+        shell: bash
+        env:
+          GH_TOKEN: ${{ github.token }}
+          PR_BODY: ${{ github.event.pull_request.body }}
+        run: |
+          config=$RUNNER_TEMP/uv-sources.toml
+          packages=
+          requirements=
+          seen=
+          references=$(printf '%s' "$PR_BODY" |
+            grep -Eo '[A-Za-z0-9._-]+/[A-Za-z0-9._-]+#[0-9]+|github\.com/[A-Za-z0-9._-]+/[A-Za-z0-9._-]+/pull/[0-9]+' |
+            sed -E -e 's|^github\.com/||' -e 's|/pull/|#|' -e 's|[/#]| |g') || true
+          while read -r owner repo number; do
+            [ -n "$number" ] || continue
+            case " $seen " in *" $owner/$repo "*) continue ;; esac
+            seen="$seen $owner/$repo"
+            package=$(sed -n '/^\[tool\.uv\.sources\]/,/^\[/p' pyproject.toml |
+              grep -F -e "\"https://github.com/$owner/$repo\"" -e "\"https://github.com/$owner/$repo.git\"" |
+              sed -E 's/^ *([^ =]+).*/\1/' |
+              head -n 1) || true
+            [ -n "$package" ] || continue
+            state=$(gh api "repos/$owner/$repo/pulls/$number" --jq .state) || state=unavailable
+            if [ "$state" != open ]; then
+              echo "$owner/$repo#$number is $state, so it is not used"
+              continue
+            fi
+            echo "Installing $package from $owner/$repo#$number"
+            packages="$packages\"$package\","
+            requirements="$requirements\"$package @ git+https://github.com/$owner/$repo@refs/pull/$number/head\","
+          done <<<"$references"
+          if [ -z "$packages" ]; then
+            echo "No sibling pull request is referenced, so every sibling stays on master"
+            exit 0
+          fi
+          printf 'no-sources-package = [%s]\nupgrade-package = [%s]\n' "$packages" "$requirements" | tee "$config"
+          echo "UV_CONFIG_FILE=$config" >>"$GITHUB_ENV"
       - name: Sync dependencies with uv
         run: uv sync --directory cle --python python3.12 --group testing
       - name: Run tests