diff --git a/.github/workflows/lane-shas.yml b/.github/workflows/lane-shas.yml
index 077fce74..f89ff433 100644
--- a/.github/workflows/lane-shas.yml
+++ b/.github/workflows/lane-shas.yml
@@ -25,7 +25,7 @@ jobs:
   verify:
     name: verify pinned lane SHAs
     runs-on: ubuntu-latest
-    timeout-minutes: 12
+    timeout-minutes: 20
 
     steps:
       - name: checkout
diff --git a/CLAIMS.md b/CLAIMS.md
index 2a5b9b40..caa2dfce 100644
--- a/CLAIMS.md
+++ b/CLAIMS.md
@@ -41,6 +41,7 @@ is a CI failure (`.github/workflows/lane-shas.yml`).
 | ADR-0098 | `demo_composition` | Demos compose from shipped modules; no parallel mechanism | `evals/demo_composition/results/v1_dev.json` | `3a3d09f3a87462737e615c2dd3481b9e13e5ff8fadee0043c37873494ded556d` |
 | ADR-0099 | `public_demo` | Public showcase runs deterministically under 30s; all claims supported | `evals/public_demo/results/v1_dev.json` | `888ddd0d12635d709f91898cf06601062168694d870f776d2b0b7710e5d68cbd` |
 | ADR-0104 | `curriculum_loop_closure` | Curriculum-sourced proposals route through single reviewed teaching path | `evals/curriculum_loop_closure/results/v1_dev.json` | `b46d56b2d209172cc3ffaf3776dc8dcfe55093f13587c5cb67372be6dfa23e8d` |
+| ADR-0131 | `math_teaching_corpus_v1` | Math teaching corpus replays deterministically; all chains pass exit criterion (correct_rate=1.0, wrong=0) | `evals/math_teaching_corpus/v1/report.json` | `eaf160d145da29f9050ede8d58bf111b0f651dd40aeae9201857d0b97e014dd4` |
 
 ## Verification
 
diff --git a/scripts/generate_claims.py b/scripts/generate_claims.py
index b526be91..c3b85523 100644
--- a/scripts/generate_claims.py
+++ b/scripts/generate_claims.py
@@ -66,6 +66,10 @@ _LANE_ADR: dict[str, tuple[str, str]] = {
         "ADR-0099",
         "Public showcase runs deterministically under 30s; all claims supported",
     ),
+    "math_teaching_corpus_v1": (
+        "ADR-0131",
+        "Math teaching corpus replays deterministically; all chains pass exit criterion (correct_rate=1.0, wrong=0)",
+    ),
 }
 
 
diff --git a/scripts/verify_lane_shas.py b/scripts/verify_lane_shas.py
index d1af4fc1..47b56eba 100644
--- a/scripts/verify_lane_shas.py
+++ b/scripts/verify_lane_shas.py
@@ -40,6 +40,7 @@ PINNED_SHAS: dict[str, str] = {
     "fabrication_control_summary": "01e1b6b711141f2b4a14551d7df3ea482d8d6dd7b364a25c509f4f8d08cda8a8",
     "demo_composition": "3a3d09f3a87462737e615c2dd3481b9e13e5ff8fadee0043c37873494ded556d",
     "public_demo": "888ddd0d12635d709f91898cf06601062168694d870f776d2b0b7710e5d68cbd",
+    "math_teaching_corpus_v1": "eaf160d145da29f9050ede8d58bf111b0f651dd40aeae9201857d0b97e014dd4",
 }
 
 
@@ -98,6 +99,12 @@ LANE_SPECS: tuple[LaneSpec, ...] = (
         runner_module="evals/public_demo/runner.py",
         report_relative="evals/public_demo/results/v1_dev.json",
     ),
+    LaneSpec(
+        lane_id="math_teaching_corpus_v1",
+        runner_module="evals/math_teaching_corpus/v1/runner.py",
+        report_relative="evals/math_teaching_corpus/v1/report.json",
+        accepts_report_flag=False,
+    ),
 )
 
 
@@ -115,7 +122,7 @@ def _invoke_runner(spec: LaneSpec, *, target_path: Path | None = None) -> Path:
         env=env,
         capture_output=True,
         text=True,
-        timeout=300,
+        timeout=900,
     )
     if result.returncode != 0:
         raise RuntimeError(
diff --git a/tests/test_adr_0131_2_teaching_corpus_lane.py b/tests/test_adr_0131_2_teaching_corpus_lane.py
index 488b04ae..49c638d2 100644
--- a/tests/test_adr_0131_2_teaching_corpus_lane.py
+++ b/tests/test_adr_0131_2_teaching_corpus_lane.py
@@ -15,10 +15,7 @@ import json
 from pathlib import Path
 
 from chat.pack_resolver import _pack_lexicon_for
-from evals.math_teaching_corpus.v1.runner import (
-    _load_cases,
-    build_report,
-)
+from evals.math_teaching_corpus.v1.runner import _load_cases
 
 _ROOT = Path(__file__).resolve().parent.parent
 _CASES_PATH = _ROOT / "evals" / "math_teaching_corpus" / "v1" / "cases.jsonl"
@@ -152,21 +149,10 @@ class TestHonestEvidence:
                 assert ref in valid_refs, f"dangling reference: {ref!r} cited in candidate {c['candidate_id']}"
 
 
-class TestLaneGate:
-    def test_lane_passes_exit_criterion(self) -> None:
-        cases = _load_cases(_CASES_PATH)
-        report = build_report(cases)
-        assert report["exit_criterion"]["passed"], (
-            f"lane gate failed: counts={report['counts']!r} "
-            f"correct_rate={report['correct_rate']!r}"
-        )
-        assert report["counts"]["wrong"] == 0, "wrong count must be zero"
-        assert report["counts"]["correct"] == len(cases), "all cases must be correct"
-
-    def test_report_is_byte_equal_across_runs(self) -> None:
-        cases = _load_cases(_CASES_PATH)
-        r1 = build_report(cases)
-        r2 = build_report(cases)
-        s1 = json.dumps(r1, sort_keys=True).encode("utf-8")
-        s2 = json.dumps(r2, sort_keys=True).encode("utf-8")
-        assert s1 == s2
+# TestLaneGate (test_lane_passes_exit_criterion + test_report_is_byte_equal_across_runs)
+# was extracted from pytest into the CI lane SHA pin job. The math_teaching_corpus_v1
+# lane runner is now invoked by .github/workflows/lane-shas.yml via
+# scripts/verify_lane_shas.py, which (a) runs the lane, (b) checks the exit criterion
+# via runner exit code, and (c) verifies the report.json byte-content against the
+# pinned SHA-256 — the same three contracts the deleted tests held, but done once
+# per PR in CI instead of twice per pytest run (~549s recovered from pytest).
diff --git a/tests/test_lane_sha_verifier.py b/tests/test_lane_sha_verifier.py
index 6b883a2e..f40c29c1 100644
--- a/tests/test_lane_sha_verifier.py
+++ b/tests/test_lane_sha_verifier.py
@@ -90,6 +90,7 @@ class TestExpectedLaneCoverage:
             "demo_composition",  # ADR-0098
             "public_demo",  # ADR-0099
             "curriculum_loop_closure",
+            "math_teaching_corpus_v1",  # ADR-0131
         }
     )