diff --git a/stores/chain.go b/stores/chain.go
index 57c8c0868..2920c8b37 100644
--- a/stores/chain.go
+++ b/stores/chain.go
@@ -38,12 +38,12 @@ func (s *SQLStore) BeginChainUpdateTx() (chain.ChainUpdateTx, error) {
 func (u *chainUpdateTx) ApplyIndex(index types.ChainIndex, created, spent []types.SiacoinElement, events []wallet.Event) error {
 	// remove spent outputs
 	for _, e := range spent {
-		// TODO: check if rows affected is > 0?
-		if err := u.tx.
+		if res := u.tx.
 			Where("output_id", hash256(e.ID)).
-			Delete(&dbWalletOutput{}).
-			Error; err != nil {
-			return err
+			Delete(&dbWalletOutput{}); res.Error != nil {
+			return res.Error
+		} else if res.RowsAffected != 1 {
+			return fmt.Errorf("spent output with id %v not found ", e.ID)
 		}
 	}
 
@@ -108,7 +108,7 @@ func (u *chainUpdateTx) ContractState(fcid types.FileContractID) (api.ContractSt
 	err := u.tx.
 		Select("state").
 		Model(&dbContract{}).
-		Where("fcid = ?", fileContractID(fcid)).
+		Where("fcid", fileContractID(fcid)).
 		Scan(&state).
 		Error
 
@@ -116,7 +116,7 @@ func (u *chainUpdateTx) ContractState(fcid types.FileContractID) (api.ContractSt
 		err = u.tx.
 			Select("state").
 			Model(&dbArchivedContract{}).
-			Where("fcid = ?", fileContractID(fcid)).
+			Where("fcid", fileContractID(fcid)).
 			Scan(&state).
 			Error
 	}
@@ -212,7 +212,7 @@ func (u *chainUpdateTx) UpdateContract(fcid types.FileContractID, revisionHeight
 	var c dbContract
 	if err := u.tx.
 		Model(&dbContract{}).
-		Where("fcid = ?", fileContractID(fcid)).
+		Where("fcid", fileContractID(fcid)).
 		Take(&c).Error; err == nil {
 		c.RevisionHeight = revisionHeight
 		if isUpdatedRevision(c.RevisionNumber) {
@@ -225,7 +225,7 @@ func (u *chainUpdateTx) UpdateContract(fcid types.FileContractID, revisionHeight
 		var ac dbArchivedContract
 		if err := u.tx.
 			Model(&dbArchivedContract{}).
-			Where("fcid = ?", fileContractID(fcid)).
+			Where("fcid", fileContractID(fcid)).
 			Take(&ac).Error; err == nil {
 			ac.RevisionHeight = revisionHeight
 			if isUpdatedRevision(ac.RevisionNumber) {
@@ -251,14 +251,14 @@ func (u *chainUpdateTx) UpdateContractState(fcid types.FileContractID, state api
 
 	if err := u.tx.
 		Model(&dbContract{}).
-		Where("fcid = ?", fileContractID(fcid)).
+		Where("fcid", fileContractID(fcid)).
 		Update("state", cs).
 		Error; err != nil {
 		return err
 	}
 	return u.tx.
 		Model(&dbArchivedContract{}).
-		Where("fcid = ?", fileContractID(fcid)).
+		Where("fcid", fileContractID(fcid)).
 		Update("state", cs).
 		Error
 }
@@ -268,14 +268,14 @@ func (u *chainUpdateTx) UpdateContractState(fcid types.FileContractID, state api
 func (u *chainUpdateTx) UpdateContractProofHeight(fcid types.FileContractID, proofHeight uint64) error {
 	if err := u.tx.
 		Model(&dbContract{}).
-		Where("fcid = ?", fileContractID(fcid)).
+		Where("fcid", fileContractID(fcid)).
 		Update("proof_height", proofHeight).
 		Error; err != nil {
 		return err
 	}
 	return u.tx.
 		Model(&dbArchivedContract{}).
-		Where("fcid = ?", fileContractID(fcid)).
+		Where("fcid", fileContractID(fcid)).
 		Update("proof_height", proofHeight).
 		Error
 }
@@ -285,7 +285,8 @@ func (u *chainUpdateTx) UpdateContractProofHeight(fcid types.FileContractID, pro
 func (u *chainUpdateTx) UpdateFailedContracts(blockHeight uint64) error {
 	return u.tx.
 		Model(&dbContract{}).
-		Where("state = ? AND ? > window_end", contractStateActive, blockHeight).
+		Where("window_end <= ?", blockHeight).
+		Where("state", contractStateActive).
 		Update("state", contractStateFailed).
 		Error
 }
diff --git a/stores/hostdb.go b/stores/hostdb.go
index caa93ae70..ae3b47e47 100644
--- a/stores/hostdb.go
+++ b/stores/hostdb.go
@@ -1184,10 +1184,10 @@ func updateProofHeight(db *gorm.DB, fcid types.FileContractID, blockHeight uint6
 
 func updateActiveAndArchivedContract(tx *gorm.DB, fcid types.FileContractID, updates map[string]interface{}) error {
 	err1 := tx.Model(&dbContract{}).
-		Where("fcid = ?", fileContractID(fcid)).
+		Where("fcid", fileContractID(fcid)).
 		Updates(updates).Error
 	err2 := tx.Model(&dbArchivedContract{}).
-		Where("fcid = ?", fileContractID(fcid)).
+		Where("fcid", fileContractID(fcid)).
 		Updates(updates).Error
 	if err1 != nil || err2 != nil {
 		return fmt.Errorf("%s; %s", err1, err2)
diff --git a/stores/metadata.go b/stores/metadata.go
index a0f31cfe8..f168f48e5 100644
--- a/stores/metadata.go
+++ b/stores/metadata.go
@@ -1389,7 +1389,7 @@ func (s *SQLStore) RecordContractSpending(ctx context.Context, records []api.Con
 		err := s.retryTransaction(ctx, func(tx *gorm.DB) error {
 			var contract dbContract
 			err := tx.Model(&dbContract{}).
-				Where("fcid = ?", fileContractID(fcid)).
+				Where("fcid", fileContractID(fcid)).
 				Joins("Host").
 				Take(&contract).Error
 			if errors.Is(err, gorm.ErrRecordNotFound) {
diff --git a/stores/metadata_test.go b/stores/metadata_test.go
index 82dc70a30..b06dd1c78 100644
--- a/stores/metadata_test.go
+++ b/stores/metadata_test.go
@@ -4152,13 +4152,7 @@ func TestSlabCleanup(t *testing.T) {
 		HealthValidUntil: 100,
 	}
 	if err := ss.db.Create(&bufferedSlab).Error; err != nil {
-		if strings.Contains(err.Error(), "database table is locked") {
-			time.Sleep(time.Second) // wait for slabs to be pruned in the background
-			err = ss.db.Create(&bufferedSlab).Error
-		}
-		if err != nil {
-			t.Fatal(err)
-		}
+		t.Fatal(err)
 	}
 	obj3 := dbObject{
 		ObjectID:   "3",