diff --git a/internal/test/rhp/v3/rhp.go b/internal/test/rhp/v3/rhp.go
index 292382eb..55f7a845 100644
--- a/internal/test/rhp/v3/rhp.go
+++ b/internal/test/rhp/v3/rhp.go
@@ -755,7 +755,6 @@ func taxAdjustedPayout(target types.Currency) types.Currency {
 
 func prepareContractRenewal(currentRevision types.FileContractRevision, renterAddress types.Address, renterKey types.PrivateKey, renterPayout, newCollateral types.Currency, hostKey types.PublicKey, hostAddr types.Address, host rhp3.HostPriceTable, endHeight uint64) (types.FileContract, types.Currency) {
 	hostValidPayout, hostMissedPayout, voidMissedPayout, basePrice := calculateRenewalPayouts(currentRevision.FileContract, newCollateral, host, endHeight)
-	renterPub := renterKey.PublicKey()
 	return types.FileContract{
 		Filesize:       currentRevision.Filesize,
 		FileMerkleRoot: currentRevision.FileMerkleRoot,
@@ -764,9 +763,10 @@ func prepareContractRenewal(currentRevision types.FileContractRevision, renterAd
 		Payout:         taxAdjustedPayout(renterPayout.Add(hostValidPayout)),
 		UnlockHash: types.Hash256(types.UnlockConditions{
 			PublicKeys: []types.UnlockKey{
-				{Algorithm: types.SpecifierEd25519, Key: renterPub[:]},
-				{Algorithm: types.SpecifierEd25519, Key: hostKey[:]},
+				renterKey.PublicKey().UnlockKey(),
+				hostKey.UnlockKey(),
 			},
+			SignaturesRequired: 2,
 		}.UnlockHash()),
 		RevisionNumber: 0,
 		ValidProofOutputs: []types.SiacoinOutput{
diff --git a/rhp/v2/contracts.go b/rhp/v2/contracts.go
index bd6e7a4a..fc7dd025 100644
--- a/rhp/v2/contracts.go
+++ b/rhp/v2/contracts.go
@@ -99,6 +99,8 @@ func validateContractRenewal(existing types.FileContractRevision, renewal types.
 		return types.ZeroCurrency, types.ZeroCurrency, types.ZeroCurrency, errors.New("wrong address for missed host output")
 	case renewal.MissedProofOutputs[2].Address != types.VoidAddress:
 		return types.ZeroCurrency, types.ZeroCurrency, types.ZeroCurrency, errors.New("wrong address for void output")
+	case renewal.UnlockHash != types.Hash256(contractUnlockConditions(hostKey, renterKey).UnlockHash()):
+		return types.ZeroCurrency, types.ZeroCurrency, types.ZeroCurrency, errors.New("incorrect unlock hash")
 	}
 
 	expectedBurn := baseHostRevenue.Add(baseRiskedCollateral)
diff --git a/rhp/v2/contracts_test.go b/rhp/v2/contracts_test.go
new file mode 100644
index 00000000..fa1d722b
--- /dev/null
+++ b/rhp/v2/contracts_test.go
@@ -0,0 +1,99 @@
+package rhp
+
+import (
+	"math"
+	"testing"
+
+	rhp2 "go.sia.tech/core/rhp/v2"
+	"go.sia.tech/core/types"
+	"lukechampine.com/frand"
+)
+
+func TestValidateContractRenewal(t *testing.T) {
+	hostKey, renterKey := types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey(), types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey()
+	hostAddress, renterAddress := types.StandardUnlockHash(hostKey), types.StandardUnlockHash(renterKey)
+	hostCollateral := types.NewCurrency64(frand.Uint64n(math.MaxUint64))
+	renterAllowance := types.NewCurrency64(frand.Uint64n(math.MaxUint64))
+
+	settings := rhp2.HostSettings{
+		MaxDuration:   math.MaxUint64,
+		MaxCollateral: types.NewCurrency(math.MaxUint64, math.MaxUint64),
+		Address:       hostAddress,
+	}
+
+	existing := types.FileContractRevision{
+		ParentID: types.FileContractID{1},
+		UnlockConditions: types.UnlockConditions{
+			PublicKeys:         []types.UnlockKey{renterKey.UnlockKey(), hostKey.UnlockKey()},
+			SignaturesRequired: 2,
+		},
+		FileContract: types.FileContract{
+			RevisionNumber: frand.Uint64n(math.MaxUint64),
+			Filesize:       frand.Uint64n(math.MaxUint64),
+			FileMerkleRoot: frand.Entropy256(),
+			WindowStart:    100,
+			WindowEnd:      300,
+			Payout:         types.ZeroCurrency, // not validated here
+			UnlockHash: types.Hash256(types.UnlockConditions{
+				PublicKeys:         []types.UnlockKey{renterKey.UnlockKey(), hostKey.UnlockKey()},
+				SignaturesRequired: 2,
+			}.UnlockHash()),
+			ValidProofOutputs: []types.SiacoinOutput{
+				{Address: renterAddress, Value: renterAllowance},
+				{Address: hostAddress, Value: hostCollateral},
+			},
+			MissedProofOutputs: []types.SiacoinOutput{
+				{Address: renterAddress, Value: renterAllowance},
+				{Address: hostAddress, Value: hostCollateral},
+				{Address: types.VoidAddress, Value: types.ZeroCurrency},
+			},
+		},
+	}
+
+	renewal := types.FileContract{
+		Filesize:       existing.Filesize,
+		FileMerkleRoot: existing.FileMerkleRoot,
+		WindowStart:    existing.WindowStart + 100,
+		WindowEnd:      existing.WindowEnd + 100,
+		ValidProofOutputs: []types.SiacoinOutput{
+			{Address: renterAddress, Value: renterAllowance},
+			{Address: hostAddress, Value: hostCollateral},
+		},
+		MissedProofOutputs: []types.SiacoinOutput{
+			{Address: renterAddress, Value: renterAllowance},
+			{Address: hostAddress, Value: hostCollateral},
+			{Address: types.VoidAddress, Value: types.ZeroCurrency},
+		},
+	}
+
+	// bad renter key
+	badRenterKey := types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey().UnlockKey()
+	renewal.UnlockHash = types.Hash256(contractUnlockConditions(hostKey.UnlockKey(), badRenterKey).UnlockHash())
+	_, _, _, err := validateContractRenewal(existing, renewal, hostKey.UnlockKey(), renterKey.UnlockKey(), types.ZeroCurrency, types.ZeroCurrency, 0, settings)
+	if err == nil || err.Error() != "incorrect unlock hash" {
+		t.Fatalf("expected unlock hash error, got %v", err)
+	}
+
+	// bad host key
+	badHostKey := types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey().UnlockKey()
+	renewal.UnlockHash = types.Hash256(contractUnlockConditions(badHostKey, renterKey.UnlockKey()).UnlockHash())
+	_, _, _, err = validateContractRenewal(existing, renewal, hostKey.UnlockKey(), renterKey.UnlockKey(), types.ZeroCurrency, types.ZeroCurrency, 0, settings)
+	if err == nil || err.Error() != "incorrect unlock hash" {
+		t.Fatalf("expected unlock hash error, got %v", err)
+	}
+
+	// original keys
+	renewal.UnlockHash = types.Hash256(contractUnlockConditions(hostKey.UnlockKey(), renterKey.UnlockKey()).UnlockHash())
+	_, _, _, err = validateContractRenewal(existing, renewal, hostKey.UnlockKey(), renterKey.UnlockKey(), types.ZeroCurrency, types.ZeroCurrency, 0, settings)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// different renter key, same host key
+	newRenterKey := types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey().UnlockKey()
+	renewal.UnlockHash = types.Hash256(contractUnlockConditions(hostKey.UnlockKey(), newRenterKey).UnlockHash())
+	_, _, _, err = validateContractRenewal(existing, renewal, hostKey.UnlockKey(), newRenterKey, types.ZeroCurrency, types.ZeroCurrency, 0, settings)
+	if err != nil {
+		t.Fatal(err)
+	}
+}
diff --git a/rhp/v3/contracts.go b/rhp/v3/contracts.go
index 02951e38..fce1ce67 100644
--- a/rhp/v3/contracts.go
+++ b/rhp/v3/contracts.go
@@ -16,6 +16,13 @@ func hashFinalRevision(clearing types.FileContractRevision, renewal types.FileCo
 	return h.Sum()
 }
 
+func contractUnlockConditions(hostKey, renterKey types.UnlockKey) types.UnlockConditions {
+	return types.UnlockConditions{
+		PublicKeys:         []types.UnlockKey{renterKey, hostKey},
+		SignaturesRequired: 2,
+	}
+}
+
 // validateContractRenewal verifies that the renewed contract is valid given the
 // old contract. A renewal is valid if the contract fields match and the
 // revision number is 0.
@@ -45,6 +52,8 @@ func validateContractRenewal(existing types.FileContractRevision, renewal types.
 		return types.ZeroCurrency, types.ZeroCurrency, errors.New("wrong address for missed host output")
 	case renewal.MissedProofOutputs[2].Address != types.VoidAddress:
 		return types.ZeroCurrency, types.ZeroCurrency, errors.New("wrong address for void output")
+	case renewal.UnlockHash != types.Hash256(contractUnlockConditions(hostKey, renterKey).UnlockHash()):
+		return types.ZeroCurrency, types.ZeroCurrency, errors.New("incorrect unlock hash")
 	}
 
 	expectedBurn := baseStorageRevenue.Add(baseRiskedCollateral)
diff --git a/rhp/v3/contracts_test.go b/rhp/v3/contracts_test.go
new file mode 100644
index 00000000..47e8ae78
--- /dev/null
+++ b/rhp/v3/contracts_test.go
@@ -0,0 +1,98 @@
+package rhp
+
+import (
+	"math"
+	"testing"
+
+	rhp3 "go.sia.tech/core/rhp/v3"
+	"go.sia.tech/core/types"
+	"lukechampine.com/frand"
+)
+
+func TestValidateContractRenewal(t *testing.T) {
+	hostKey, renterKey := types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey(), types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey()
+	hostAddress, renterAddress := types.StandardUnlockHash(hostKey), types.StandardUnlockHash(renterKey)
+	hostCollateral := types.NewCurrency64(frand.Uint64n(math.MaxUint64))
+	renterAllowance := types.NewCurrency64(frand.Uint64n(math.MaxUint64))
+
+	pt := rhp3.HostPriceTable{
+		MaxDuration:   math.MaxUint64,
+		MaxCollateral: types.NewCurrency(math.MaxUint64, math.MaxUint64),
+	}
+
+	existing := types.FileContractRevision{
+		ParentID: types.FileContractID{1},
+		UnlockConditions: types.UnlockConditions{
+			PublicKeys:         []types.UnlockKey{renterKey.UnlockKey(), hostKey.UnlockKey()},
+			SignaturesRequired: 2,
+		},
+		FileContract: types.FileContract{
+			RevisionNumber: frand.Uint64n(math.MaxUint64),
+			Filesize:       frand.Uint64n(math.MaxUint64),
+			FileMerkleRoot: frand.Entropy256(),
+			WindowStart:    100,
+			WindowEnd:      300,
+			Payout:         types.ZeroCurrency, // not validated here
+			UnlockHash: types.Hash256(types.UnlockConditions{
+				PublicKeys:         []types.UnlockKey{renterKey.UnlockKey(), hostKey.UnlockKey()},
+				SignaturesRequired: 2,
+			}.UnlockHash()),
+			ValidProofOutputs: []types.SiacoinOutput{
+				{Address: renterAddress, Value: renterAllowance},
+				{Address: hostAddress, Value: hostCollateral},
+			},
+			MissedProofOutputs: []types.SiacoinOutput{
+				{Address: renterAddress, Value: renterAllowance},
+				{Address: hostAddress, Value: hostCollateral},
+				{Address: types.VoidAddress, Value: types.ZeroCurrency},
+			},
+		},
+	}
+
+	renewal := types.FileContract{
+		Filesize:       existing.Filesize,
+		FileMerkleRoot: existing.FileMerkleRoot,
+		WindowStart:    existing.WindowStart + 100,
+		WindowEnd:      existing.WindowEnd + 100,
+		ValidProofOutputs: []types.SiacoinOutput{
+			{Address: renterAddress, Value: renterAllowance},
+			{Address: hostAddress, Value: hostCollateral},
+		},
+		MissedProofOutputs: []types.SiacoinOutput{
+			{Address: renterAddress, Value: renterAllowance},
+			{Address: hostAddress, Value: hostCollateral},
+			{Address: types.VoidAddress, Value: types.ZeroCurrency},
+		},
+	}
+
+	// bad renter key
+	badRenterKey := types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey().UnlockKey()
+	renewal.UnlockHash = types.Hash256(contractUnlockConditions(hostKey.UnlockKey(), badRenterKey).UnlockHash())
+	_, _, err := validateContractRenewal(existing, renewal, hostKey.UnlockKey(), renterKey.UnlockKey(), hostAddress, types.ZeroCurrency, types.ZeroCurrency, pt)
+	if err == nil || err.Error() != "incorrect unlock hash" {
+		t.Fatalf("expected unlock hash error, got %v", err)
+	}
+
+	// bad host key
+	badHostKey := types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey().UnlockKey()
+	renewal.UnlockHash = types.Hash256(contractUnlockConditions(badHostKey, renterKey.UnlockKey()).UnlockHash())
+	_, _, err = validateContractRenewal(existing, renewal, hostKey.UnlockKey(), renterKey.UnlockKey(), hostAddress, types.ZeroCurrency, types.ZeroCurrency, pt)
+	if err == nil || err.Error() != "incorrect unlock hash" {
+		t.Fatalf("expected unlock hash error, got %v", err)
+	}
+
+	// original keys
+	renewal.UnlockHash = types.Hash256(contractUnlockConditions(hostKey.UnlockKey(), renterKey.UnlockKey()).UnlockHash())
+	_, _, err = validateContractRenewal(existing, renewal, hostKey.UnlockKey(), renterKey.UnlockKey(), hostAddress, types.ZeroCurrency, types.ZeroCurrency, pt)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// different renter key, same host key
+	newRenterKey := types.NewPrivateKeyFromSeed(frand.Bytes(32)).PublicKey().UnlockKey()
+	renewal.UnlockHash = types.Hash256(contractUnlockConditions(hostKey.UnlockKey(), newRenterKey).UnlockHash())
+	_, _, err = validateContractRenewal(existing, renewal, hostKey.UnlockKey(), newRenterKey, hostAddress, types.ZeroCurrency, types.ZeroCurrency, pt)
+	if err != nil {
+		t.Fatal(err)
+	}
+}