diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/ConstraintStorage.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/ConstraintStorage.kt
index 0b5642a7659..efd65ce805e 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/ConstraintStorage.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/ConstraintStorage.kt
@@ -1,23 +1,12 @@
 /*
- * Copyright 2010-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * Copyright 2000-2018 JetBrains s.r.o. 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.resolve.calls.inference.model
 
 import org.jetbrains.kotlin.resolve.calls.inference.substitute
-import org.jetbrains.kotlin.resolve.calls.model.*
+import org.jetbrains.kotlin.resolve.calls.model.KotlinCallDiagnostic
 import org.jetbrains.kotlin.types.TypeConstructor
 import org.jetbrains.kotlin.types.TypeSubstitutor
 import org.jetbrains.kotlin.types.UnwrappedType
@@ -51,6 +40,7 @@ interface ConstraintStorage {
     val initialConstraints: List<InitialConstraint>
     val maxTypeDepthFromInitialConstraints: Int
     val errors: List<KotlinCallDiagnostic>
+    val hasContradiction: Boolean
     val fixedTypeVariables: Map<TypeConstructor, UnwrappedType>
 
     object Empty : ConstraintStorage {
@@ -59,6 +49,7 @@ interface ConstraintStorage {
         override val initialConstraints: List<InitialConstraint> get() = emptyList()
         override val maxTypeDepthFromInitialConstraints: Int get() = 1
         override val errors: List<KotlinCallDiagnostic> get() = emptyList()
+        override val hasContradiction: Boolean get() = false
         override val fixedTypeVariables: Map<TypeConstructor, UnwrappedType> get() = emptyMap()
     }
 }
diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt
index 9e6a04b8ee6..41342630e46 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/MutableConstraintStorage.kt
@@ -1,23 +1,13 @@
 /*
- * Copyright 2010-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * Copyright 2000-2018 JetBrains s.r.o. 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.resolve.calls.inference.model
 
 import org.jetbrains.kotlin.resolve.calls.inference.trimToSize
 import org.jetbrains.kotlin.resolve.calls.model.KotlinCallDiagnostic
+import org.jetbrains.kotlin.resolve.calls.tower.isSuccess
 import org.jetbrains.kotlin.types.TypeConstructor
 import org.jetbrains.kotlin.types.UnwrappedType
 import java.util.*
@@ -102,5 +92,6 @@ internal class MutableConstraintStorage : ConstraintStorage {
     override val initialConstraints: MutableList<InitialConstraint> = ArrayList()
     override var maxTypeDepthFromInitialConstraints: Int = 1
     override val errors: MutableList<KotlinCallDiagnostic> = ArrayList()
+    override val hasContradiction: Boolean get() = errors.any { !it.candidateApplicability.isSuccess }
     override val fixedTypeVariables: MutableMap<TypeConstructor, UnwrappedType> = LinkedHashMap()
 }
\ No newline at end of file
diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt
index 62690012c08..352be20896e 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/model/NewConstraintSystemImpl.kt
@@ -1,17 +1,6 @@
 /*
- * Copyright 2010-2017 JetBrains s.r.o.
- *
- * Licensed under the Apache License, Version 2.0 (the "License");
- * you may not use this file except in compliance with the License.
- * You may obtain a copy of the License at
- *
- * http://www.apache.org/licenses/LICENSE-2.0
- *
- * Unless required by applicable law or agreed to in writing, software
- * distributed under the License is distributed on an "AS IS" BASIS,
- * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
- * See the License for the specific language governing permissions and
- * limitations under the License.
+ * Copyright 2000-2018 JetBrains s.r.o. 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.resolve.calls.inference.model
@@ -24,10 +13,8 @@ import org.jetbrains.kotlin.resolve.calls.inference.components.KotlinConstraintS
 import org.jetbrains.kotlin.resolve.calls.inference.components.NewTypeSubstitutor
 import org.jetbrains.kotlin.resolve.calls.inference.components.ResultTypeResolver
 import org.jetbrains.kotlin.resolve.calls.model.KotlinCallDiagnostic
-import org.jetbrains.kotlin.resolve.calls.tower.isSuccess
 import org.jetbrains.kotlin.types.TypeConstructor
 import org.jetbrains.kotlin.types.UnwrappedType
-import org.jetbrains.kotlin.types.checker.NewTypeVariableConstructor
 import org.jetbrains.kotlin.types.typeUtil.contains
 import org.jetbrains.kotlin.types.typeUtil.isUnit
 import org.jetbrains.kotlin.utils.SmartList
@@ -157,7 +144,7 @@ class NewConstraintSystemImpl(
 
     // ConstraintSystemBuilder, KotlinConstraintSystemCompleter.Context
     override val hasContradiction: Boolean
-        get() = diagnostics.any { !it.candidateApplicability.isSuccess }.apply {
+        get() = storage.hasContradiction.also {
             checkState(
                 State.FREEZED,
                 State.BUILDING,