diff --git a/pkg/services/oracle/request.go b/pkg/services/oracle/request.go
index 4c59cbbaa..088b205d8 100644
--- a/pkg/services/oracle/request.go
+++ b/pkg/services/oracle/request.go
@@ -172,6 +172,7 @@ func (o *Oracle) processRequest(priv *keys.PrivateKey, req request) error {
 	o.Log.Debug("oracle request processed", zap.String("url", req.Req.URL), zap.Int("code", int(resp.Code)), zap.String("result", string(resp.Result)))
 
 	currentHeight := o.Chain.BlockHeight()
+	vubInc := o.Chain.GetConfig().MaxValidUntilBlockIncrement
 	_, h, err := o.Chain.GetTransaction(req.Req.OriginalTxID)
 	if err != nil {
 		if !errors.Is(err, storage.ErrKeyNotFound) {
@@ -180,10 +181,14 @@ func (o *Oracle) processRequest(priv *keys.PrivateKey, req request) error {
 		// The only reason tx can be not found is if it wasn't yet persisted from DAO.
 		h = currentHeight
 	}
+	h += vubInc // Main tx is only valid for RequestHeight + ValidUntilBlock.
 	tx, err := o.CreateResponseTx(int64(req.Req.GasForResponse), h, resp)
 	if err != nil {
 		return err
 	}
+	for h <= currentHeight { // Backup tx must be valid in any event.
+		h += vubInc
+	}
 	backupTx, err := o.CreateResponseTx(int64(req.Req.GasForResponse), h, &transaction.OracleResponse{
 		ID:   req.ID,
 		Code: transaction.ConsensusUnreachable,
diff --git a/pkg/services/oracle/response.go b/pkg/services/oracle/response.go
index aef834c29..6b5f9d541 100644
--- a/pkg/services/oracle/response.go
+++ b/pkg/services/oracle/response.go
@@ -81,10 +81,10 @@ func readResponse(rc gio.ReadCloser, limit int) ([]byte, error) {
 }
 
 // CreateResponseTx creates unsigned oracle response transaction.
-func (o *Oracle) CreateResponseTx(gasForResponse int64, height uint32, resp *transaction.OracleResponse) (*transaction.Transaction, error) {
+func (o *Oracle) CreateResponseTx(gasForResponse int64, vub uint32, resp *transaction.OracleResponse) (*transaction.Transaction, error) {
 	tx := transaction.New(o.oracleResponse, 0)
 	tx.Nonce = uint32(resp.ID)
-	tx.ValidUntilBlock = height + o.Chain.GetConfig().MaxValidUntilBlockIncrement
+	tx.ValidUntilBlock = vub
 	tx.Attributes = []transaction.Attribute{{
 		Type:  transaction.OracleResponseT,
 		Value: resp,