diff --git a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DelegatingDataFlowInfo.kt b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DelegatingDataFlowInfo.kt
index c197ba2c11d..30c19e106fe 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DelegatingDataFlowInfo.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/resolve/calls/smartcasts/DelegatingDataFlowInfo.kt
@@ -20,15 +20,14 @@ import com.google.common.collect.*
 import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.config.LanguageVersionSettings
-import org.jetbrains.kotlin.types.*
+import org.jetbrains.kotlin.resolve.calls.smartcasts.Nullability.NOT_NULL
 import org.jetbrains.kotlin.types.KotlinType
 import org.jetbrains.kotlin.types.TypeUtils
-import org.jetbrains.kotlin.types.typeUtil.*
-
+import org.jetbrains.kotlin.types.isFlexible
+import org.jetbrains.kotlin.types.typeUtil.isSubtypeOf
+import org.jetbrains.kotlin.utils.newLinkedHashSetWithExpectedSize
 import java.util.*
 
-import org.jetbrains.kotlin.resolve.calls.smartcasts.Nullability.NOT_NULL
-
 internal class DelegatingDataFlowInfo private constructor(
         private val parent: DataFlowInfo?,
         private val nullabilityInfo: ImmutableMap<DataFlowValue, Nullability>,
@@ -121,7 +120,7 @@ internal class DelegatingDataFlowInfo private constructor(
             return types
         }
 
-        val enrichedTypes = Sets.newHashSetWithExpectedSize<KotlinType>(types.size + 1)
+        val enrichedTypes = newLinkedHashSetWithExpectedSize<KotlinType>(types.size + 1)
         val originalType = key.type
         if (originalType.isMarkedNullable) {
             enrichedTypes.add(TypeUtils.makeNotNullable(originalType))