diff --git a/node/src/main/scala/com/wavesplatform/Application.scala b/node/src/main/scala/com/wavesplatform/Application.scala
index 73e314ce97..ae91db955e 100644
--- a/node/src/main/scala/com/wavesplatform/Application.scala
+++ b/node/src/main/scala/com/wavesplatform/Application.scala
@@ -5,6 +5,11 @@ import java.security.Security
 import java.util.concurrent.ConcurrentHashMap
 import java.util.concurrent.atomic.AtomicBoolean
 
+import scala.concurrent.{Await, Future}
+import scala.concurrent.ExecutionContext.Implicits.global
+import scala.concurrent.duration._
+import scala.util.{Failure, Success, Try}
+
 import akka.actor.ActorSystem
 import akka.http.scaladsl.Http
 import akka.http.scaladsl.Http.ServerBinding
@@ -22,7 +27,7 @@ import com.wavesplatform.api.http.leasing.LeaseApiRoute
 import com.wavesplatform.common.state.ByteStr
 import com.wavesplatform.consensus.PoSSelector
 import com.wavesplatform.consensus.nxt.api.http.NxtConsensusApiRoute
-import com.wavesplatform.database.{DBExt, Keys, openDB}
+import com.wavesplatform.database.{openDB, DBExt, Keys}
 import com.wavesplatform.events.{BlockchainUpdateTriggers, UtxEvent}
 import com.wavesplatform.extensions.{Context, Extension}
 import com.wavesplatform.features.EstimatorProvider._
@@ -33,12 +38,12 @@ import com.wavesplatform.metrics.Metrics
 import com.wavesplatform.mining.{Miner, MinerDebugInfo, MinerImpl}
 import com.wavesplatform.network._
 import com.wavesplatform.settings.WavesSettings
-import com.wavesplatform.state.appender.{BlockAppender, ExtensionAppender, MicroblockAppender}
 import com.wavesplatform.state.{Blockchain, BlockchainUpdaterImpl, Diff, Height}
-import com.wavesplatform.transaction.smart.script.trace.TracedResult
+import com.wavesplatform.state.appender.{BlockAppender, ExtensionAppender, MicroblockAppender}
 import com.wavesplatform.transaction.{Asset, DiscardedBlocks, Transaction}
-import com.wavesplatform.utils.Schedulers._
+import com.wavesplatform.transaction.smart.script.trace.TracedResult
 import com.wavesplatform.utils._
+import com.wavesplatform.utils.Schedulers._
 import com.wavesplatform.utx.{UtxPool, UtxPoolImpl}
 import com.wavesplatform.wallet.Wallet
 import io.netty.channel.Channel
@@ -55,11 +60,6 @@ import org.influxdb.dto.Point
 import org.iq80.leveldb.DB
 import org.slf4j.LoggerFactory
 
-import scala.concurrent.ExecutionContext.Implicits.global
-import scala.concurrent.duration._
-import scala.concurrent.{Await, Future}
-import scala.util.{Failure, Success, Try}
-
 class Application(val actorSystem: ActorSystem, val settings: WavesSettings, configRoot: ConfigObject, time: NTP) extends ScorexLogging {
   app =>
 
@@ -351,7 +351,8 @@ class Application(val actorSystem: ActorSystem, val settings: WavesSettings, con
           scoreStatsReporter,
           configRoot,
           loadBalanceHistory,
-          levelDB.loadStateHash
+          levelDB.loadStateHash,
+          () => utxStorage.priorityPool.compositeBlockchain
         ),
         AssetsApiRoute(
           settings.restAPISettings,
@@ -541,8 +542,8 @@ object Application extends ScorexLogging {
     Metrics.start(settings.metrics, time)
 
     def dumpMinerConfig(): Unit = {
-      import settings.synchronizationSettings.microBlockSynchronizer
       import settings.{minerSettings => miner}
+      import settings.synchronizationSettings.microBlockSynchronizer
 
       Metrics.write(
         Point
diff --git a/node/src/main/scala/com/wavesplatform/api/http/DebugApiRoute.scala b/node/src/main/scala/com/wavesplatform/api/http/DebugApiRoute.scala
index 4f825045c8..3d8e6a0026 100644
--- a/node/src/main/scala/com/wavesplatform/api/http/DebugApiRoute.scala
+++ b/node/src/main/scala/com/wavesplatform/api/http/DebugApiRoute.scala
@@ -3,6 +3,11 @@ package com.wavesplatform.api.http
 import java.net.{InetAddress, InetSocketAddress, URI}
 import java.util.concurrent.ConcurrentMap
 
+import scala.concurrent.{ExecutionContext, Future}
+import scala.concurrent.duration._
+import scala.util.{Failure, Success}
+import scala.util.control.NonFatal
+
 import akka.http.scaladsl.common.{EntityStreamingSupport, JsonEntityStreamingSupport}
 import akka.http.scaladsl.model.StatusCodes
 import akka.http.scaladsl.model.headers.Accept
@@ -12,18 +17,18 @@ import cats.implicits._
 import cats.kernel.Monoid
 import com.typesafe.config.{ConfigObject, ConfigRenderOptions}
 import com.wavesplatform.account.Address
-import com.wavesplatform.api.common.CommonTransactionsApi.TransactionMeta
 import com.wavesplatform.api.common.{CommonAccountsApi, CommonAssetsApi, CommonTransactionsApi}
+import com.wavesplatform.api.common.CommonTransactionsApi.TransactionMeta
 import com.wavesplatform.api.http.TransactionsApiRoute.TransactionJsonSerializer
 import com.wavesplatform.common.state.ByteStr
 import com.wavesplatform.lang.ValidationError
 import com.wavesplatform.mining.{Miner, MinerDebugInfo}
 import com.wavesplatform.network.{PeerDatabase, PeerInfo, _}
 import com.wavesplatform.settings.{RestAPISettings, WavesSettings}
-import com.wavesplatform.state.diffs.TransactionDiffer
 import com.wavesplatform.state.{Blockchain, LeaseBalance, NG, Portfolio, StateHash}
-import com.wavesplatform.transaction.TxValidationError.{GenericError, InvalidRequestSignature}
+import com.wavesplatform.state.diffs.TransactionDiffer
 import com.wavesplatform.transaction._
+import com.wavesplatform.transaction.TxValidationError.{GenericError, InvalidRequestSignature}
 import com.wavesplatform.transaction.smart.script.trace.TracedResult
 import com.wavesplatform.utils.{ScorexLogging, Time}
 import com.wavesplatform.utx.UtxPool
@@ -31,13 +36,8 @@ import com.wavesplatform.wallet.Wallet
 import io.netty.channel.Channel
 import monix.eval.{Coeval, Task}
 import monix.execution.Scheduler
-import play.api.libs.json.Json.JsValueWrapper
 import play.api.libs.json._
-
-import scala.concurrent.duration._
-import scala.concurrent.{ExecutionContext, Future}
-import scala.util.control.NonFatal
-import scala.util.{Failure, Success}
+import play.api.libs.json.Json.JsValueWrapper
 
 case class DebugApiRoute(
     ws: WavesSettings,
@@ -58,7 +58,8 @@ case class DebugApiRoute(
     scoreReporter: Coeval[RxScoreObserver.Stats],
     configRoot: ConfigObject,
     loadBalanceHistory: Address => Seq[(Int, Long)],
-    loadStateHash: Int => Option[StateHash]
+    loadStateHash: Int => Option[StateHash],
+    priorityPoolBlockchain: () => Blockchain
 ) extends ApiRoute
     with AuthRoute
     with ScorexLogging {
@@ -224,13 +225,14 @@ case class DebugApiRoute(
 
   def validate: Route =
     path("validate")(jsonPost[JsObject] { jsv =>
-      val startTime = System.nanoTime()
-
+      val blockchain = priorityPoolBlockchain()
+      val startTime  = System.nanoTime()
+      
       val parsedTransaction = TransactionFactory.fromSignedRequest(jsv)
 
       val tracedDiff = for {
         tx   <- TracedResult(parsedTransaction)
-        diff <- TransactionDiffer(blockchain.lastBlockTimestamp, time.correctedTime())(blockchain, tx)
+        diff <- TransactionDiffer.forceValidate(blockchain.lastBlockTimestamp, time.correctedTime())(blockchain, tx)
       } yield (tx, diff)
 
       val error = tracedDiff.resultE match {
diff --git a/node/src/test/scala/com/wavesplatform/history/Domain.scala b/node/src/test/scala/com/wavesplatform/history/Domain.scala
index 4b2497bc8d..33170bf268 100644
--- a/node/src/test/scala/com/wavesplatform/history/Domain.scala
+++ b/node/src/test/scala/com/wavesplatform/history/Domain.scala
@@ -3,15 +3,15 @@ package com.wavesplatform.history
 import cats.syntax.option._
 import com.wavesplatform.account.Address
 import com.wavesplatform.api.common.{AddressPortfolio, AddressTransactions}
-import com.wavesplatform.block.Block.BlockId
 import com.wavesplatform.block.{Block, MicroBlock}
+import com.wavesplatform.block.Block.BlockId
 import com.wavesplatform.common.state.ByteStr
 import com.wavesplatform.common.utils.EitherExt2
 import com.wavesplatform.database.{DBExt, LevelDBWriter}
 import com.wavesplatform.lang.ValidationError
 import com.wavesplatform.state._
-import com.wavesplatform.transaction.Asset.IssuedAsset
 import com.wavesplatform.transaction.{BlockchainUpdater, _}
+import com.wavesplatform.transaction.Asset.IssuedAsset
 import org.iq80.leveldb.DB
 
 case class Domain(db: DB, blockchainUpdater: BlockchainUpdaterImpl, levelDBWriter: LevelDBWriter) {
diff --git a/node/src/test/scala/com/wavesplatform/http/DebugApiRouteSpec.scala b/node/src/test/scala/com/wavesplatform/http/DebugApiRouteSpec.scala
index 48a0a49035..9807569c96 100644
--- a/node/src/test/scala/com/wavesplatform/http/DebugApiRouteSpec.scala
+++ b/node/src/test/scala/com/wavesplatform/http/DebugApiRouteSpec.scala
@@ -1,30 +1,33 @@
 package com.wavesplatform.http
 
+import scala.util.Random
+
 import akka.http.scaladsl.model.{ContentTypes, HttpEntity, StatusCodes}
+import com.wavesplatform.{BlockchainStubHelpers, NTPTime, TestValues, TestWallet}
 import com.wavesplatform.api.http.ApiError.ApiKeyNotValid
 import com.wavesplatform.api.http.DebugApiRoute
 import com.wavesplatform.block.SignedBlockHeader
 import com.wavesplatform.common.state.ByteStr
 import com.wavesplatform.common.utils._
+import com.wavesplatform.db.WithDomain
+import com.wavesplatform.features.BlockchainFeatures
 import com.wavesplatform.it.util._
 import com.wavesplatform.lagonaki.mocks.TestBlock
 import com.wavesplatform.lang.v1.estimator.v3.ScriptEstimatorV3
 import com.wavesplatform.lang.v1.traits.domain.Issue
 import com.wavesplatform.network.PeerDatabase
 import com.wavesplatform.settings.WavesSettings
-import com.wavesplatform.state.StateHash.SectionId
 import com.wavesplatform.state.{AccountScriptInfo, AssetDescription, AssetScriptInfo, Blockchain, Height, NG, StateHash}
+import com.wavesplatform.state.StateHash.SectionId
 import com.wavesplatform.transaction.TxHelpers
 import com.wavesplatform.transaction.assets.exchange.OrderType
 import com.wavesplatform.transaction.smart.InvokeScriptTransaction
 import com.wavesplatform.transaction.smart.InvokeScriptTransaction.Payment
 import com.wavesplatform.transaction.smart.script.ScriptCompiler
-import com.wavesplatform.{BlockchainStubHelpers, NTPTime, TestValues, TestWallet}
+import com.wavesplatform.transaction.transfer.TransferTransaction
 import monix.eval.Task
 import org.scalamock.scalatest.PathMockFactory
-import play.api.libs.json.{JsArray, JsObject, JsValue, Json}
-
-import scala.util.Random
+import play.api.libs.json.{JsArray, JsObject, Json, JsValue}
 
 //noinspection ScalaStyle
 class DebugApiRouteSpec
@@ -33,7 +36,8 @@ class DebugApiRouteSpec
     with TestWallet
     with NTPTime
     with PathMockFactory
-    with BlockchainStubHelpers {
+    with BlockchainStubHelpers
+    with WithDomain {
 
   val wavesSettings = WavesSettings.default()
   val configObject  = wavesSettings.config.root()
@@ -68,7 +72,8 @@ class DebugApiRouteSpec
       _ => Seq.empty, {
         case 2 => Some(testStateHash)
         case _ => None
-      }
+      },
+      () => blockchain
     )
   import debugApiRoute._
 
@@ -94,14 +99,34 @@ class DebugApiRouteSpec
   }
 
   routePath("/validate") - {
+    def routeWithBlockchain(blockchain: Blockchain with NG) =
+      debugApiRoute.copy(blockchain = blockchain, priorityPoolBlockchain = () => blockchain).route
+    
+
+    def validatePost(tx: TransferTransaction) =
+      Post(routePath("/validate"), HttpEntity(ContentTypes.`application/json`, tx.json().toString()))
+
+    "takes the priority pool into account" in withDomain(domainSettingsWithFeatures(BlockchainFeatures.NG)) { d =>
+      d.appendBlock(TxHelpers.genesis(TxHelpers.defaultAddress))
+      d.appendBlock(TxHelpers.transfer(to = TxHelpers.secondAddress, amount = 1.waves + TestValues.fee))
+
+      val route = debugApiRoute.copy(priorityPoolBlockchain = () => d.blockchain).route
+      val tx = TxHelpers.transfer(TxHelpers.secondSigner, TestValues.address, 1.waves)
+      validatePost(tx) ~> route ~> check {
+        val json = Json.parse(responseAs[String])
+        (json \ "valid").as[Boolean] shouldBe true
+        (json \ "validationTime").as[Int] shouldBe 1000 +- 1000
+      }
+    }
+
     "valid tx" in {
       val blockchain = createBlockchainStub()
       (blockchain.balance _).when(TxHelpers.defaultSigner.publicKey.toAddress, *).returns(Long.MaxValue)
 
-      val route = debugApiRoute.copy(blockchain = blockchain).route
+      val route = routeWithBlockchain(blockchain)
 
       val tx = TxHelpers.transfer(TxHelpers.defaultSigner, TestValues.address, 1.waves)
-      Post(routePath("/validate"), HttpEntity(ContentTypes.`application/json`, tx.json().toString())) ~> route ~> check {
+      validatePost(tx) ~> route ~> check {
         val json = Json.parse(responseAs[String])
         (json \ "valid").as[Boolean] shouldBe true
         (json \ "validationTime").as[Int] shouldBe 1000 +- 1000
@@ -112,10 +137,10 @@ class DebugApiRouteSpec
       val blockchain = createBlockchainStub()
       (blockchain.balance _).when(TxHelpers.defaultSigner.publicKey.toAddress, *).returns(0)
 
-      val route = debugApiRoute.copy(blockchain = blockchain).route
+      val route = routeWithBlockchain(blockchain)
 
       val tx = TxHelpers.transfer(TxHelpers.defaultSigner, TestValues.address, Long.MaxValue)
-      Post(routePath("/validate"), HttpEntity(ContentTypes.`application/json`, tx.json().toString())) ~> route ~> check {
+      validatePost(tx) ~> route ~> check {
         val json = Json.parse(responseAs[String])
         (json \ "valid").as[Boolean] shouldBe false
         (json \ "validationTime").as[Int] shouldBe 1000 +- 1000
@@ -150,7 +175,7 @@ class DebugApiRouteSpec
           )
       }
 
-      val route = debugApiRoute.copy(blockchain = blockchain).route
+      val route = routeWithBlockchain(blockchain)
       val tx    = TxHelpers.exchange(TxHelpers.order(OrderType.BUY, TestValues.asset), TxHelpers.order(OrderType.SELL, TestValues.asset))
       jsonPost(routePath("/validate"), tx.json()) ~> route ~> check {
         val json = Json.parse(responseAs[String])
@@ -249,8 +274,7 @@ class DebugApiRouteSpec
         (blockchain.hasAccountScript _).when(*).returns(true)
       }
 
-      val route = debugApiRoute.copy(blockchain = blockchain).route
-
+      val route = routeWithBlockchain(blockchain)
       def testFunction(name: String, result: InvokeScriptTransaction => String) = withClue(s"function $name") {
         val tx = TxHelpers.invoke(TxHelpers.defaultAddress, name, fee = 102500000)
 
@@ -518,7 +542,7 @@ class DebugApiRouteSpec
             )
           )
       }
-      val route = debugApiRoute.copy(blockchain = blockchain).route
+      val route = routeWithBlockchain(blockchain)
       val tx    = TxHelpers.transfer(TxHelpers.defaultSigner, TxHelpers.defaultAddress, 1, TestValues.asset)
 
       jsonPost(routePath("/validate"), tx.json()) ~> route ~> check {