diff --git a/extern/sector-storage/ffiwrapper/sealer_test.go b/extern/sector-storage/ffiwrapper/sealer_test.go
index ae1ede7eb..acbd9ca21 100644
--- a/extern/sector-storage/ffiwrapper/sealer_test.go
+++ b/extern/sector-storage/ffiwrapper/sealer_test.go
@@ -168,50 +168,34 @@ func (s *seal) unseal(t *testing.T, sb *Sealer, sp *basicfs.Provider, si abi.Sec
 	}
 }
 
-func post(t *testing.T, sealer *Sealer, seals ...seal) time.Time {
-	/*randomness := abi.PoStRandomness{0, 9, 2, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 45, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 7}
+func post(t *testing.T, sealer *Sealer, skipped []abi.SectorID, seals ...seal) {
+	randomness := abi.PoStRandomness{0, 9, 2, 7, 6, 5, 4, 3, 2, 1, 0, 9, 8, 7, 6, 45, 3, 2, 1, 0, 9, 8, 7, 6, 5, 4, 3, 2, 1, 0, 9, 7}
 
-	sis := make([]abi.SectorInfo, len(seals))
+	sis := make([]saproof.SectorInfo, len(seals))
 	for i, s := range seals {
-		sis[i] = abi.SectorInfo{
-			RegisteredProof: sealProofType,
+		sis[i] = saproof.SectorInfo{
+			SealProof: sealProofType,
 			SectorNumber:    s.id.Number,
 			SealedCID:       s.cids.Sealed,
 		}
 	}
 
-	candidates, err := sealer.GenerateEPostCandidates(context.TODO(), seals[0].id.Miner, sis, randomness, []abi.SectorNumber{})
-	if err != nil {
-		t.Fatalf("%+v", err)
-	}*/
-
-	fmt.Println("skipping post")
-
-	genCandidates := time.Now()
-
-	/*if len(candidates) != 1 {
-		t.Fatal("expected 1 candidate")
+	proofs, skp, err := sealer.GenerateWindowPoSt(context.TODO(), seals[0].id.Miner, sis, randomness)
+	if len(skipped) > 0 {
+		require.Error(t, err)
+		require.EqualValues(t, skipped, skp)
+		return
 	}
 
-	candidatesPrime := make([]abi.PoStCandidate, len(candidates))
-	for idx := range candidatesPrime {
-		candidatesPrime[idx] = candidates[idx].Candidate
-	}
-
-	proofs, err := sealer.ComputeElectionPoSt(context.TODO(), seals[0].id.Miner, sis, randomness, candidatesPrime)
 	if err != nil {
 		t.Fatalf("%+v", err)
 	}
 
-	ePoStChallengeCount := ElectionPostChallengeCount(uint64(len(sis)), 0)
-
-	ok, err := ProofVerifier.VerifyElectionPost(context.TODO(), abi.PoStVerifyInfo{
+	ok, err := ProofVerifier.VerifyWindowPoSt(context.TODO(), saproof.WindowPoStVerifyInfo{
 		Randomness:      randomness,
-		Candidates:      candidatesPrime,
 		Proofs:          proofs,
-		EligibleSectors: sis,
+		ChallengedSectors: sis,
 		Prover:          seals[0].id.Miner,
-		ChallengeCount:  ePoStChallengeCount,
 	})
 	if err != nil {
 		t.Fatalf("%+v", err)
@@ -219,8 +203,21 @@ func post(t *testing.T, sealer *Sealer, seals ...seal) time.Time {
 	if !ok {
 		t.Fatal("bad post")
 	}
-	*/
-	return genCandidates
+}
+
+func corrupt(t *testing.T, sealer *Sealer, id abi.SectorID) {
+	paths, done, err := sealer.sectors.AcquireSector(context.Background(), id, stores.FTSealed, 0, stores.PathStorage)
+	require.NoError(t, err)
+	defer done()
+
+	log.Infof("corrupt %s", paths.Sealed)
+	f, err := os.OpenFile(paths.Sealed, os.O_RDWR, 0664)
+	require.NoError(t, err)
+
+	_, err = f.WriteAt(bytes.Repeat([]byte{'d'}, 2048), 0)
+	require.NoError(t, err)
+
+	require.NoError(t, f.Close())
 }
 
 func getGrothParamFileAndVerifyingKeys(s abi.SectorSize) {
@@ -299,11 +296,11 @@ func TestSealAndVerify(t *testing.T) {
 
 	commit := time.Now()
 
-	genCandidiates := post(t, sb, s)
+	post(t, sb, nil, s)
 
 	epost := time.Now()
 
-	post(t, sb, s)
+	post(t, sb, nil, s)
 
 	if err := sb.FinalizeSector(context.TODO(), si, nil); err != nil {
 		t.Fatalf("%+v", err)
@@ -313,8 +310,7 @@ func TestSealAndVerify(t *testing.T) {
 
 	fmt.Printf("PreCommit: %s\n", precommit.Sub(start).String())
 	fmt.Printf("Commit: %s\n", commit.Sub(precommit).String())
-	fmt.Printf("GenCandidates: %s\n", genCandidiates.Sub(commit).String())
-	fmt.Printf("EPoSt: %s\n", epost.Sub(genCandidiates).String())
+	fmt.Printf("EPoSt: %s\n", epost.Sub(commit).String())
 }
 
 func TestSealPoStNoCommit(t *testing.T) {
@@ -370,16 +366,15 @@ func TestSealPoStNoCommit(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	genCandidiates := post(t, sb, s)
+	post(t, sb, nil, s)
 
 	epost := time.Now()
 
 	fmt.Printf("PreCommit: %s\n", precommit.Sub(start).String())
-	fmt.Printf("GenCandidates: %s\n", genCandidiates.Sub(precommit).String())
-	fmt.Printf("EPoSt: %s\n", epost.Sub(genCandidiates).String())
+	fmt.Printf("EPoSt: %s\n", epost.Sub(precommit).String())
 }
 
-func TestSealAndVerify2(t *testing.T) {
+func TestSealAndVerify3(t *testing.T) {
 	defer requireFDsClosed(t, openFDs(t))
 
 	if runtime.NumCPU() < 10 && os.Getenv("CI") == "" { // don't bother on slow hardware
@@ -419,22 +414,32 @@ func TestSealAndVerify2(t *testing.T) {
 
 	si1 := abi.SectorID{Miner: miner, Number: 1}
 	si2 := abi.SectorID{Miner: miner, Number: 2}
+	si3 := abi.SectorID{Miner: miner, Number: 3}
 
 	s1 := seal{id: si1}
 	s2 := seal{id: si2}
+	s3 := seal{id: si3}
 
-	wg.Add(2)
+	wg.Add(3)
 	go s1.precommit(t, sb, si1, wg.Done) //nolint: staticcheck
 	time.Sleep(100 * time.Millisecond)
 	go s2.precommit(t, sb, si2, wg.Done) //nolint: staticcheck
+	time.Sleep(100 * time.Millisecond)
+	go s3.precommit(t, sb, si3, wg.Done) //nolint: staticcheck
 	wg.Wait()
 
-	wg.Add(2)
+	wg.Add(3)
 	go s1.commit(t, sb, wg.Done) //nolint: staticcheck
 	go s2.commit(t, sb, wg.Done) //nolint: staticcheck
+	go s3.commit(t, sb, wg.Done) //nolint: staticcheck
 	wg.Wait()
 
-	post(t, sb, s1, s2)
+	post(t, sb, nil, s1, s2, s3)
+
+	corrupt(t, sb, si1)
+	corrupt(t, sb, si2)
+
+	post(t, sb, []abi.SectorID{si1, si2}, s1, s2, s3)
 }
 
 func BenchmarkWriteWithAlignment(b *testing.B) {