diff --git a/.github/docker/Dockerfile.ci b/.github/docker/Dockerfile.ci
index 9dff7c0a..ebf4a4d1 100644
--- a/.github/docker/Dockerfile.ci
+++ b/.github/docker/Dockerfile.ci
@@ -89,10 +89,14 @@ RUN for i in 1 2 3; do \
     && fc-cache -f \
     && rm -rf /var/lib/apt/lists/*
 
-# Pre-install dependencies (cached layer — only rebuilds when package.json changes)
-COPY package.json /workspace/
+# Pre-install dependencies (cached layer — only rebuilds when package.json or
+# bun.lock changes). Copy BOTH so install is deterministic and matches local
+# resolution. Without bun.lock here, bun install resolved transitive deps
+# differently in CI vs local (observed on v1.28.0.0: socks landed but
+# smart-buffer + ip-address didn't make it into the cached node_modules).
+COPY package.json bun.lock /workspace/
 WORKDIR /workspace
-RUN bun install && rm -rf /tmp/*
+RUN bun install --frozen-lockfile && rm -rf /tmp/*
 
 # Install Playwright Chromium to a shared location accessible by all users
 ENV PLAYWRIGHT_BROWSERS_PATH=/opt/playwright-browsers
diff --git a/.github/workflows/ci-image.yml b/.github/workflows/ci-image.yml
index 00d38637..1ca283ad 100644
--- a/.github/workflows/ci-image.yml
+++ b/.github/workflows/ci-image.yml
@@ -9,6 +9,7 @@ on:
     paths:
       - '.github/docker/Dockerfile.ci'
       - 'package.json'
+      - 'bun.lock'
   # Manual trigger
   workflow_dispatch:
 
@@ -22,7 +23,7 @@ jobs:
       - uses: actions/checkout@v4
 
       # Copy lockfile + package.json into Docker build context
-      - run: cp package.json .github/docker/
+      - run: cp package.json bun.lock .github/docker/
 
       - uses: docker/login-action@v3
         with:
diff --git a/.github/workflows/evals-periodic.yml b/.github/workflows/evals-periodic.yml
index 20035c45..df16bcbc 100644
--- a/.github/workflows/evals-periodic.yml
+++ b/.github/workflows/evals-periodic.yml
@@ -25,7 +25,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - id: meta
-        run: echo "tag=${{ env.IMAGE }}:${{ hashFiles('.github/docker/Dockerfile.ci', 'package.json') }}" >> "$GITHUB_OUTPUT"
+        run: echo "tag=${{ env.IMAGE }}:${{ hashFiles('.github/docker/Dockerfile.ci', 'package.json', 'bun.lock') }}" >> "$GITHUB_OUTPUT"
 
       - uses: docker/login-action@v3
         with:
@@ -43,7 +43,7 @@ jobs:
           fi
 
       - if: steps.check.outputs.exists == 'false'
-        run: cp package.json .github/docker/
+        run: cp package.json bun.lock .github/docker/
 
       - if: steps.check.outputs.exists == 'false'
         uses: docker/build-push-action@v6
diff --git a/.github/workflows/evals.yml b/.github/workflows/evals.yml
index a7b1fd99..45d4b693 100644
--- a/.github/workflows/evals.yml
+++ b/.github/workflows/evals.yml
@@ -25,7 +25,7 @@ jobs:
       - uses: actions/checkout@v4
 
       - id: meta
-        run: echo "tag=${{ env.IMAGE }}:${{ hashFiles('.github/docker/Dockerfile.ci', 'package.json') }}" >> "$GITHUB_OUTPUT"
+        run: echo "tag=${{ env.IMAGE }}:${{ hashFiles('.github/docker/Dockerfile.ci', 'package.json', 'bun.lock') }}" >> "$GITHUB_OUTPUT"
 
       - uses: docker/login-action@v3
         with:
@@ -43,7 +43,7 @@ jobs:
           fi
 
       - if: steps.check.outputs.exists == 'false'
-        run: cp package.json .github/docker/
+        run: cp package.json bun.lock .github/docker/
 
       - if: steps.check.outputs.exists == 'false'
         uses: docker/build-push-action@v6