diff --git a/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeTraverser.kt b/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeTraverser.kt
index a80fef37b65..a37de877b43 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeTraverser.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/cfg/PseudocodeTraverser.kt
@@ -208,7 +208,7 @@ fun Pseudocode.getStartInstruction(traversalOrder: TraversalOrder): Instruction
 fun Pseudocode.getLastInstruction(traversalOrder: TraversalOrder): Instruction =
         if (traversalOrder == FORWARD) sinkInstruction else enterInstruction
 
-fun Pseudocode.getInstructions(traversalOrder: TraversalOrder): MutableList<Instruction> =
+fun Pseudocode.getInstructions(traversalOrder: TraversalOrder): List<Instruction> =
         if (traversalOrder == FORWARD) instructions else reversedInstructions
 
 fun Instruction.getNextInstructions(traversalOrder: TraversalOrder): Collection<Instruction> =
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/Pseudocode.kt b/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/Pseudocode.kt
index 561f97f594f..b7bb5390131 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/Pseudocode.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/Pseudocode.kt
@@ -14,58 +14,41 @@
  * limitations under the License.
  */
 
-package org.jetbrains.kotlin.cfg.pseudocode;
+package org.jetbrains.kotlin.cfg.pseudocode
 
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.kotlin.cfg.pseudocode.instructions.Instruction;
-import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.LocalFunctionDeclarationInstruction;
-import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.SubroutineEnterInstruction;
-import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.SubroutineExitInstruction;
-import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.SubroutineSinkInstruction;
-import org.jetbrains.kotlin.psi.KtElement;
+import org.jetbrains.kotlin.cfg.pseudocode.instructions.Instruction
+import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.LocalFunctionDeclarationInstruction
+import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.SubroutineEnterInstruction
+import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.SubroutineExitInstruction
+import org.jetbrains.kotlin.cfg.pseudocode.instructions.special.SubroutineSinkInstruction
+import org.jetbrains.kotlin.psi.KtElement
 
-import java.util.List;
-import java.util.Set;
+interface Pseudocode {
+    val correspondingElement: KtElement
 
-public interface Pseudocode {
-    @NotNull
-    KtElement getCorrespondingElement();
+    val parent: Pseudocode?
 
-    @Nullable
-    Pseudocode getParent();
+    val localDeclarations: Set<LocalFunctionDeclarationInstruction>
 
-    @NotNull
-    Set<LocalFunctionDeclarationInstruction> getLocalDeclarations();
+    val instructions: List<Instruction>
 
-    @NotNull
-    List<Instruction> getInstructions();
+    val reversedInstructions: List<Instruction>
 
-    @NotNull
-    List<Instruction> getReversedInstructions();
+    val instructionsIncludingDeadCode: List<Instruction>
 
-    @NotNull
-    List<Instruction> getInstructionsIncludingDeadCode();
+    val exitInstruction: SubroutineExitInstruction
 
-    @NotNull
-    SubroutineExitInstruction getExitInstruction();
+    val sinkInstruction: SubroutineSinkInstruction
 
-    @NotNull
-    SubroutineSinkInstruction getSinkInstruction();
+    val enterInstruction: SubroutineEnterInstruction
 
-    @NotNull
-    SubroutineEnterInstruction getEnterInstruction();
+    fun getElementValue(element: KtElement?): PseudoValue?
 
-    @Nullable
-    PseudoValue getElementValue(@Nullable KtElement element);
+    fun getValueElements(value: PseudoValue?): List<KtElement>
 
-    @NotNull
-    List<? extends KtElement> getValueElements(@Nullable PseudoValue value);
+    fun getUsages(value: PseudoValue?): List<Instruction>
 
-    @NotNull
-    List<? extends Instruction> getUsages(@Nullable PseudoValue value);
+    fun isSideEffectFree(instruction: Instruction): Boolean
 
-    boolean isSideEffectFree(@NotNull Instruction instruction);
-
-    Pseudocode copy();
+    fun copy(): Pseudocode
 }
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/PseudocodeImpl.java b/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/PseudocodeImpl.java
index 7861364af13..ade52174200 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/PseudocodeImpl.java
+++ b/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/PseudocodeImpl.java
@@ -278,15 +278,15 @@ public class PseudocodeImpl implements Pseudocode {
 
     @NotNull
     @Override
-    public List<? extends KtElement> getValueElements(@Nullable PseudoValue value) {
-        List<? extends KtElement> result = elementsToValues.getKeysByValue(value);
+    public List<KtElement> getValueElements(@Nullable PseudoValue value) {
+        List<KtElement> result = elementsToValues.getKeysByValue(value);
         return result != null ? result : Collections.<KtElement>emptyList();
     }
 
     @NotNull
     @Override
-    public List<? extends Instruction> getUsages(@Nullable PseudoValue value) {
-        List<? extends Instruction> result = valueUsages.get(value);
+    public List<Instruction> getUsages(@Nullable PseudoValue value) {
+        List<Instruction> result = valueUsages.get(value);
         return result != null ? result : Collections.<Instruction>emptyList();
     }
 
diff --git a/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/pseudocodeUtils.kt b/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/pseudocodeUtils.kt
index 906745545c6..4b192b28388 100644
--- a/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/pseudocodeUtils.kt
+++ b/compiler/frontend/src/org/jetbrains/kotlin/cfg/pseudocode/pseudocodeUtils.kt
@@ -149,7 +149,7 @@ fun getExpectedTypePredicate(
                     val returnElement = it.element
                     val functionDescriptor = when(returnElement) {
                         is KtReturnExpression -> returnElement.getTargetFunctionDescriptor(bindingContext)
-                        else -> bindingContext[DECLARATION_TO_DESCRIPTOR, pseudocode.getCorrespondingElement()]
+                        else -> bindingContext[DECLARATION_TO_DESCRIPTOR, pseudocode.correspondingElement]
                     }
                     addSubtypesOf((functionDescriptor as? CallableDescriptor)?.getReturnType())
                 }
@@ -278,7 +278,7 @@ fun Pseudocode.getElementValuesRecursively(element: KtElement): List<PseudoValue
 
     fun Pseudocode.collectValues() {
         getElementValue(element)?.let { results.add(it) }
-        for (localFunction in getLocalDeclarations()) {
+        for (localFunction in localDeclarations) {
             localFunction.body.collectValues()
         }
     }
@@ -303,8 +303,8 @@ fun KtElement.getContainingPseudocode(context: BindingContext): Pseudocode? {
 }
 
 fun Pseudocode.getPseudocodeByElement(element: KtElement): Pseudocode? {
-    if (getCorrespondingElement() == element) return this
+    if (correspondingElement == element) return this
 
-    getLocalDeclarations().forEach { decl -> decl.body.getPseudocodeByElement(element)?.let { return it } }
+    localDeclarations.forEach { decl -> decl.body.getPseudocodeByElement(element)?.let { return it } }
     return null
 }
\ No newline at end of file