diff --git a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/TypeCheckerContextForConstraintSystem.kt b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/TypeCheckerContextForConstraintSystem.kt
index 4c2a39f80a8..7fae9e1f315 100644
--- a/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/TypeCheckerContextForConstraintSystem.kt
+++ b/compiler/resolution/src/org/jetbrains/kotlin/resolve/calls/inference/components/TypeCheckerContextForConstraintSystem.kt
@@ -225,8 +225,8 @@ abstract class TypeCheckerContextForConstraintSystem : TypeCheckerContext(errorT
             with(NewKotlinTypeChecker) { this@TypeCheckerContextForConstraintSystem.isSubtypeOf(subType, superType) }
 
     private fun assertInputTypes(subType: UnwrappedType, superType: UnwrappedType) {
-        fun correctSubType(subType: SimpleType) = subType.isSingleClassifierType || subType.isIntersectionType || isMyTypeVariable(subType)
-        fun correctSuperType(superType: SimpleType) = superType.isSingleClassifierType || isMyTypeVariable(superType)
+        fun correctSubType(subType: SimpleType) = subType.isSingleClassifierType || subType.isIntersectionType || isMyTypeVariable(subType) || subType.isError
+        fun correctSuperType(superType: SimpleType) = superType.isSingleClassifierType || superType.isIntersectionType || isMyTypeVariable(superType) || superType.isError
 
         assert(subType.bothBounds(::correctSubType)) {
             "Not singleClassifierType and not intersection subType: $subType"
diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/checker/NewKotlinTypeChecker.kt b/core/descriptors/src/org/jetbrains/kotlin/types/checker/NewKotlinTypeChecker.kt
index 60859d5d4d9..0ca16a093bb 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/checker/NewKotlinTypeChecker.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/checker/NewKotlinTypeChecker.kt
@@ -121,7 +121,10 @@ object NewKotlinTypeChecker : KotlinTypeChecker {
         val newSubType = transformToNewType(subType)
         val newSuperType = transformToNewType(superType)
 
-        checkSubtypeForSpecialCases(newSubType.lowerIfFlexible(), newSuperType.upperIfFlexible())?.let { return it }
+        checkSubtypeForSpecialCases(newSubType.lowerIfFlexible(), newSuperType.upperIfFlexible())?.let {
+            addSubtypeConstraint(newSubType, newSuperType)
+            return it
+        }
 
         // we should add constraints with flexible types, otherwise we never get flexible type as answer in constraint system
         addSubtypeConstraint(newSubType, newSuperType)?.let { return it }