diff --git a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/types/LazyJavaTypeResolver.kt b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/types/LazyJavaTypeResolver.kt
index 91014269ff2..20c448932b7 100644
--- a/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/types/LazyJavaTypeResolver.kt
+++ b/core/descriptor.loader.java/src/org/jetbrains/kotlin/load/java/lazy/types/LazyJavaTypeResolver.kt
@@ -294,18 +294,19 @@ class LazyJavaTypeResolver(
         }
 
         private class Impl(lowerBound: KotlinType, upperBound: KotlinType) :
-                DelegatingFlexibleType(lowerBound, upperBound, FlexibleJavaClassifierTypeFactory), CustomTypeVariable, Specificity {
+                DelegatingFlexibleType(lowerBound, upperBound, FlexibleJavaClassifierTypeFactory), CustomTypeVariable {
+
+            override val delegateType: KotlinType get() = lowerBound
 
             override fun <T : TypeCapability> getCapability(capabilityClass: Class<T>): T? {
                 @Suppress("UNCHECKED_CAST")
-                return when (capabilityClass) {
-                    CustomTypeVariable::class.java, Specificity::class.java -> this as T
-                    else -> super.getCapability(capabilityClass)
-                }
+                if (capabilityClass == CustomTypeVariable::class.java) return this as T
+
+                return super.getCapability(capabilityClass)
             }
 
-            override val isTypeVariable: Boolean = lowerBound.getConstructor() == upperBound.getConstructor()
-                                                   && lowerBound.getConstructor().getDeclarationDescriptor() is TypeParameterDescriptor
+            override val isTypeVariable: Boolean = lowerBound.constructor == upperBound.constructor
+                                                   && lowerBound.constructor.declarationDescriptor is TypeParameterDescriptor
 
             override fun substitutionResult(replacement: KotlinType): KotlinType {
                 return if (replacement.isFlexible()) replacement
@@ -323,7 +324,7 @@ class LazyJavaTypeResolver(
                 // Int! >< Int?
                 if (otherType.isFlexible()) return Specificity.Relation.DONT_KNOW
                 // Int? >< Int!
-                if (otherType.isMarkedNullable()) return Specificity.Relation.DONT_KNOW
+                if (otherType.isMarkedNullable) return Specificity.Relation.DONT_KNOW
                 // Int! lessSpecific Int
                 return Specificity.Relation.LESS_SPECIFIC
             }
diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/dynamicTypes.kt b/core/descriptors/src/org/jetbrains/kotlin/types/dynamicTypes.kt
index d2cce6020c0..a881d0068c5 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/dynamicTypes.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/dynamicTypes.kt
@@ -43,19 +43,12 @@ object DynamicTypeFactory : FlexibleTypeFactory {
         return Impl(lowerBound, upperBound)
     }
 
-    private class Impl(lowerBound: KotlinType, upperBound: KotlinType) : DelegatingFlexibleType(lowerBound, upperBound, DynamicTypeFactory),  Dynamicity, Specificity, NullAwareness, FlexibleTypeDelegation {
-        companion object {
-            internal val capabilityClasses = hashSetOf(
-                    Dynamicity::class.java,
-                    Specificity::class.java,
-                    NullAwareness::class.java,
-                    FlexibleTypeDelegation::class.java
-            )
-        }
+    private class Impl(lowerBound: KotlinType, upperBound: KotlinType) :
+            DelegatingFlexibleType(lowerBound, upperBound, DynamicTypeFactory), Dynamicity {
 
         override fun <T : TypeCapability> getCapability(capabilityClass: Class<T>): T? {
             @Suppress("UNCHECKED_CAST")
-            if (capabilityClass in capabilityClasses) return this as T
+            if (capabilityClass == Dynamicity::class.java) return this as T
 
             return super.getCapability(capabilityClass)
         }
@@ -71,6 +64,6 @@ object DynamicTypeFactory : FlexibleTypeFactory {
             return createDynamicType(delegateType.builtIns)
         }
 
-        override fun computeIsNullable() = false
+        override fun isMarkedNullable() = false
     }
 }
diff --git a/core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt b/core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt
index f8e3aacfab7..5c0722b060a 100644
--- a/core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt
+++ b/core/descriptors/src/org/jetbrains/kotlin/types/flexibleTypes.kt
@@ -87,24 +87,19 @@ fun KotlinType.upperIfFlexible(): KotlinType = if (this.isFlexible()) this.flexi
 
 interface NullAwareness : TypeCapability {
     fun makeNullableAsSpecified(nullable: Boolean): KotlinType
-    fun computeIsNullable(): Boolean
 }
 
-interface FlexibleTypeDelegation : TypeCapability {
-    val delegateType: KotlinType
-}
-
-open class DelegatingFlexibleType protected constructor(
+abstract class DelegatingFlexibleType protected constructor(
         override val lowerBound: KotlinType,
         override val upperBound: KotlinType,
         override val factory: FlexibleTypeFactory
-) : DelegatingType(), NullAwareness, Flexibility, FlexibleTypeDelegation {
+) : DelegatingType(), NullAwareness, Flexibility, Specificity {
     companion object {
         internal val capabilityClasses = hashSetOf(
                 NullAwareness::class.java,
                 Flexibility::class.java,
                 SubtypingRepresentatives::class.java,
-                FlexibleTypeDelegation::class.java
+                Specificity::class.java
         )
 
         @JvmField
@@ -131,6 +126,8 @@ open class DelegatingFlexibleType protected constructor(
         }
     }
 
+    protected abstract val delegateType: KotlinType
+
     override fun <T : TypeCapability> getCapability(capabilityClass: Class<T>): T? {
         @Suppress("UNCHECKED_CAST")
         if (capabilityClass in capabilityClasses) return this as T
@@ -143,17 +140,10 @@ open class DelegatingFlexibleType protected constructor(
                               TypeUtils.makeNullableAsSpecified(upperBound, nullable))
     }
 
-    override fun computeIsNullable() = delegateType.isMarkedNullable
-
-    override fun isMarkedNullable(): Boolean = getCapability(NullAwareness::class.java)!!.computeIsNullable()
-
-    override val delegateType: KotlinType
-        get() {
-            runAssertions()
-            return lowerBound
-        }
-
-    override fun getDelegate() = getCapability(FlexibleTypeDelegation::class.java)!!.delegateType
+    final override fun getDelegate(): KotlinType {
+        runAssertions()
+        return delegateType
+    }
 
     override fun toString() = "('$lowerBound'..'$upperBound')"
 }