diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirCallResolver.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirCallResolver.kt
index 95f213a240d..2c1196cdfc1 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirCallResolver.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/FirCallResolver.kt
@@ -19,6 +19,9 @@ import org.jetbrains.kotlin.fir.references.builder.buildResolvedNamedReference
 import org.jetbrains.kotlin.fir.references.impl.FirSimpleNamedReference
 import org.jetbrains.kotlin.fir.resolve.*
 import org.jetbrains.kotlin.fir.resolve.calls.*
+import org.jetbrains.kotlin.fir.resolve.calls.tower.FirTowerResolver
+import org.jetbrains.kotlin.fir.resolve.calls.tower.TowerGroup
+import org.jetbrains.kotlin.fir.resolve.calls.tower.TowerResolveManager
 import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeAmbiguityError
 import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeInapplicableCandidateError
 import org.jetbrains.kotlin.fir.resolve.diagnostics.ConeUnresolvedNameError
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/CandidateCollector.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/CandidateCollector.kt
index f08e74f96e4..3d75aead411 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/CandidateCollector.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/CandidateCollector.kt
@@ -6,6 +6,7 @@
 package org.jetbrains.kotlin.fir.resolve.calls
 
 import org.jetbrains.kotlin.fir.resolve.BodyResolveComponents
+import org.jetbrains.kotlin.fir.resolve.calls.tower.TowerGroup
 
 open class CandidateCollector(
     val components: BodyResolveComponents,
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/FirTowerResolver.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolver.kt
similarity index 96%
rename from compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/FirTowerResolver.kt
rename to compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolver.kt
index 9a96b2fb6fe..da6f4427b35 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/FirTowerResolver.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolver.kt
@@ -3,9 +3,10 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.resolve.calls
+package org.jetbrains.kotlin.fir.resolve.calls.tower
 
 import org.jetbrains.kotlin.fir.resolve.BodyResolveComponents
+import org.jetbrains.kotlin.fir.resolve.calls.*
 
 class FirTowerResolver(
     private val components: BodyResolveComponents,
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/FirTowerResolverSession.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolverSession.kt
similarity index 99%
rename from compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/FirTowerResolverSession.kt
rename to compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolverSession.kt
index 17cb0abb1eb..847b3d66154 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/FirTowerResolverSession.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/FirTowerResolverSession.kt
@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.resolve.calls
+package org.jetbrains.kotlin.fir.resolve.calls.tower
 
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.fir.FirSession
@@ -17,6 +17,7 @@ import org.jetbrains.kotlin.fir.expressions.builder.FirQualifiedAccessExpression
 import org.jetbrains.kotlin.fir.references.FirSuperReference
 import org.jetbrains.kotlin.fir.resolve.BodyResolveComponents
 import org.jetbrains.kotlin.fir.resolve.buildResolvedQualifierForClass
+import org.jetbrains.kotlin.fir.resolve.calls.*
 import org.jetbrains.kotlin.fir.resolve.scope
 import org.jetbrains.kotlin.fir.resolve.transformQualifiedAccessUsingSmartcastInfo
 import org.jetbrains.kotlin.fir.resolve.transformers.body.resolve.firUnsafe
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerGroup.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerGroup.kt
similarity index 98%
rename from compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerGroup.kt
rename to compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerGroup.kt
index 7a7770cf6c1..1195e7a9693 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerGroup.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerGroup.kt
@@ -3,7 +3,7 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.resolve.calls
+package org.jetbrains.kotlin.fir.resolve.calls.tower
 
 sealed class TowerGroupKind(private val index: Int) : Comparable<TowerGroupKind> {
     abstract class WithDepth(index: Int, val depth: Int) : TowerGroupKind(index)
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerLevelHandler.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevelHandler.kt
similarity index 98%
rename from compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerLevelHandler.kt
rename to compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevelHandler.kt
index ca9043b8644..b757d847415 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerLevelHandler.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevelHandler.kt
@@ -3,10 +3,11 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.resolve.calls
+package org.jetbrains.kotlin.fir.resolve.calls.tower
 
 import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.expressions.FirResolvedQualifier
+import org.jetbrains.kotlin.fir.resolve.calls.*
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerLevels.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevels.kt
similarity index 98%
rename from compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerLevels.kt
rename to compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevels.kt
index d6cc24b5e66..ee4bdcdde6e 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerLevels.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerLevels.kt
@@ -1,9 +1,9 @@
 /*
- * Copyright 2010-2019 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Copyright 2010-2020 JetBrains s.r.o. and Kotlin Programming Language contributors.
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.resolve.calls
+package org.jetbrains.kotlin.fir.resolve.calls.tower
 
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirCallableMemberDeclaration
@@ -13,6 +13,7 @@ import org.jetbrains.kotlin.fir.declarations.isStatic
 import org.jetbrains.kotlin.fir.expressions.FirExpression
 import org.jetbrains.kotlin.fir.resolve.BodyResolveComponents
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
+import org.jetbrains.kotlin.fir.resolve.calls.*
 import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.ProcessorAction
 import org.jetbrains.kotlin.fir.scopes.impl.FirAbstractImportingScope
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerResolveManager.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerResolveManager.kt
similarity index 95%
rename from compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerResolveManager.kt
rename to compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerResolveManager.kt
index 918ceb3b97b..2f5505a0fb5 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/TowerResolveManager.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/calls/tower/TowerResolveManager.kt
@@ -3,8 +3,9 @@
  * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
  */
 
-package org.jetbrains.kotlin.fir.resolve.calls
+package org.jetbrains.kotlin.fir.resolve.calls.tower
 
+import org.jetbrains.kotlin.fir.resolve.calls.CandidateCollector
 import java.util.*
 import kotlin.coroutines.*
 
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractImportingScope.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractImportingScope.kt
index efed80d67e3..4734ae1b3ed 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractImportingScope.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractImportingScope.kt
@@ -9,7 +9,7 @@ import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirResolvedImport
 import org.jetbrains.kotlin.fir.declarations.expandedConeType
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
-import org.jetbrains.kotlin.fir.resolve.calls.TowerScopeLevel
+import org.jetbrains.kotlin.fir.resolve.calls.tower.TowerScopeLevel
 import org.jetbrains.kotlin.fir.resolve.toSymbol
 import org.jetbrains.kotlin.fir.scopes.FirScope
 import org.jetbrains.kotlin.fir.scopes.unsubstitutedScope
@@ -17,7 +17,6 @@ import org.jetbrains.kotlin.fir.symbols.CallableId
 import org.jetbrains.kotlin.fir.symbols.impl.*
 import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.name.Name
-import org.jetbrains.kotlin.utils.addToStdlib.cast
 
 abstract class FirAbstractImportingScope(
     session: FirSession,
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractSimpleImportingScope.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractSimpleImportingScope.kt
index c4afe54e612..e9395b4c703 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractSimpleImportingScope.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractSimpleImportingScope.kt
@@ -9,7 +9,7 @@ import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirResolvedImport
 import org.jetbrains.kotlin.fir.resolve.FirSymbolProvider
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
-import org.jetbrains.kotlin.fir.resolve.calls.TowerScopeLevel
+import org.jetbrains.kotlin.fir.resolve.calls.tower.TowerScopeLevel
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassifierSymbol
 import org.jetbrains.kotlin.name.ClassId
diff --git a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractStarImportingScope.kt b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractStarImportingScope.kt
index d0afffa62de..ce743d3f7d6 100644
--- a/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractStarImportingScope.kt
+++ b/compiler/fir/resolve/src/org/jetbrains/kotlin/fir/scopes/impl/FirAbstractStarImportingScope.kt
@@ -8,7 +8,7 @@ package org.jetbrains.kotlin.fir.scopes.impl
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.declarations.FirResolvedImport
 import org.jetbrains.kotlin.fir.resolve.ScopeSession
-import org.jetbrains.kotlin.fir.resolve.calls.TowerScopeLevel
+import org.jetbrains.kotlin.fir.resolve.calls.tower.TowerScopeLevel
 import org.jetbrains.kotlin.fir.symbols.impl.FirCallableSymbol
 import org.jetbrains.kotlin.fir.symbols.impl.FirClassifierSymbol
 import org.jetbrains.kotlin.name.ClassId