diff --git a/evalharness/eval/recipes/agent.py b/evalharness/eval/recipes/agent.py
index d28d102..117cc8f 100644
--- a/evalharness/eval/recipes/agent.py
+++ b/evalharness/eval/recipes/agent.py
@@ -269,7 +269,12 @@ def _official_swebench_eval(instance_meta: dict, patch: str, timeout: int = 1800
     image_name = test_spec.instance_image_key
     container = client.containers.run(
         image_name, command='tail -f /dev/null', detach=True,
-        name=f'eh-swe-official-{test_spec.instance_id[:40]}')
+        name=f'eh-swe-official-{test_spec.instance_id[:40]}',
+        # the official eval_script runs `pip install -e .[test]`; pypi.org
+        # is unreachable from this host's containers -> same tuna mirror
+        # as the agent containers
+        environment={'PIP_INDEX_URL':
+                     'https://pypi.tuna.tsinghua.edu.cn/simple'})
     try:
         patch_file = log_dir / 'patch.diff'
         patch_file.write_text(patch or '')