diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 2e5a177ba..0c4b33923 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -971,6 +971,7 @@ jobs:
     if: github.event_name == 'pull_request' || github.ref == 'refs/heads/main'
     permissions:
       contents: read
+      pull-requests: read # Read the current title/body when a check is rerun after an edit.
 
     steps:
       - uses: actions/checkout@d23441a48e516b6c34aea4fa41551a30e30af803 # v6.1.0
@@ -980,6 +981,8 @@ jobs:
           persist-credentials: false
       - name: Validate PR source or every integrated main commit and breaking footer
         run: python3 -m scripts.check_main_policies conventional
+        env:
+          GH_TOKEN: ${{ github.token }}
 
   downstream-imports:
     name: Downstream import smoke (representative consumer symbols)
diff --git a/scripts/check_main_policies.py b/scripts/check_main_policies.py
index 70bfa8e5d..49844838e 100644
--- a/scripts/check_main_policies.py
+++ b/scripts/check_main_policies.py
@@ -173,12 +173,21 @@ def event_context() -> tuple[str, str, dict[str, Any]]:
     return kind, target, event
 
 
-def conventional(kind: str, target: str, event: dict[str, Any]) -> dict[str, Any]:
+def conventional(
+    kind: str, target: str, event: dict[str, Any], *, api: GitHub | None = None
+) -> dict[str, Any]:
     if kind == "push":
         commits = main_commits(target)
     else:
         pr = event["pull_request"]
-        validate_message(pr["title"] + "\n\n" + (pr["body"] or ""))
+        # Reruns retain the original webhook payload, including an obsolete PR
+        # description. Read the editable message again without changing which
+        # checkout and commits this run is allowed to validate.
+        if api is None:
+            api = GitHub(os.environ["GH_TOKEN"])
+        current = api.repo(f"pulls/{pr['number']}")
+        require(current["head"]["sha"] == pr["head"]["sha"], "PR head changed; run current CI")
+        validate_message(current["title"] + "\n\n" + (current["body"] or ""))
         head, base = pr["head"]["sha"], pr["base"]["sha"]
         require(SHA.fullmatch(head) and SHA.fullmatch(base), "invalid PR source identities")
         fork = git("merge-base", base, head)
diff --git a/tests/conformance/signing/test_ip_pinned_transport.py b/tests/conformance/signing/test_ip_pinned_transport.py
index b9292b8e5..a5f0bbefb 100644
--- a/tests/conformance/signing/test_ip_pinned_transport.py
+++ b/tests/conformance/signing/test_ip_pinned_transport.py
@@ -349,7 +349,10 @@ def test_real_tls_handshake_still_validates_hostname() -> None:
     # machines. The intent is "handshake didn't reject", not speed.
     with httpx.Client(transport=transport, timeout=60.0) as client:
         response = client.get("https://example.com/")
-    assert response.status_code == 200
+    # Any HTTP response proves the handshake and hostname check passed (a
+    # certificate mismatch raises before a response exists). The origin's
+    # own status is not under test: example.com intermittently answers 503.
+    assert 100 <= response.status_code < 600
 
 
 @pytest.mark.skipif(not _internet_ok(), reason="no outbound internet")
diff --git a/tests/test_main_release_policies.py b/tests/test_main_release_policies.py
index 66d48c269..6d6e97bf1 100644
--- a/tests/test_main_release_policies.py
+++ b/tests/test_main_release_policies.py
@@ -100,6 +100,61 @@ def test_every_post_release_integration_has_real_agreement(history: list[str]) -
     assert policies.conventional("push", history[-1], {})["commits"] == history[1:]
 
 
+def test_conventional_rerun_reads_the_corrected_pr_body(history: list[str]) -> None:
+    api = PolicyAPI(history)
+    pr = {
+        "number": 1174,
+        "head": {"sha": history[-1]},
+        "base": {"sha": history[0]},
+        "title": BREAKING_SUBJECT,
+        "body": "Missing the breaking footer in the original webhook.",
+    }
+    api.data["pulls/1174"] = {**pr, "body": BREAKING_FOOTER}
+
+    result = policies.conventional("pull_request", history[-1], {"pull_request": pr}, api=api)
+
+    assert result["commits"] == history[1:]
+    assert api.reads == ["pulls/1174"]
+
+
+def test_conventional_rerun_rejects_a_newly_invalid_pr_message(history: list[str]) -> None:
+    api = PolicyAPI(history)
+    pr = {
+        "number": 1174,
+        "head": {"sha": history[-1]},
+        "base": {"sha": history[0]},
+        "title": BREAKING_SUBJECT,
+        "body": BREAKING_FOOTER,
+    }
+    api.data["pulls/1174"] = {**pr, "body": None}
+
+    with pytest.raises(ReleaseRejectedError, match="BREAKING CHANGE"):
+        policies.conventional("pull_request", history[-1], {"pull_request": pr}, api=api)
+
+
+def test_conventional_rerun_cannot_validate_a_different_pr_head(history: list[str]) -> None:
+    api = PolicyAPI(history)
+    pr = {
+        "number": 1174,
+        "head": {"sha": history[-1]},
+        "base": {"sha": history[0]},
+        "title": "fix: valid contribution",
+        "body": "",
+    }
+    api.data["pulls/1174"] = {**pr, "head": {"sha": "a" * 40}}
+
+    with pytest.raises(ReleaseRejectedError, match="PR head changed"):
+        policies.conventional("pull_request", history[-1], {"pull_request": pr}, api=api)
+
+
+def test_conventional_workflow_can_read_current_pr_metadata() -> None:
+    workflow = yaml.safe_load((policies.ROOT / ".github/workflows/ci.yml").read_text())
+    job = workflow["jobs"]["conventional-commits"]
+    assert job["permissions"] == {"contents": "read", "pull-requests": "read"}
+    step = next(s for s in job["steps"] if "check_main_policies conventional" in s.get("run", ""))
+    assert step["env"]["GH_TOKEN"] == "${{ github.token }}"
+
+
 @pytest.mark.parametrize(
     "case",
     [