diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClassInitializer.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClassInitializer.java
index fdefca96372..c8c1606c15a 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClassInitializer.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClassInitializer.java
@@ -22,7 +22,7 @@ import org.jetbrains.annotations.NotNull;
 /**
  * @author max
  */
-public class JetClassInitializer extends JetDeclaration implements JetStatementExpression {
+public class JetClassInitializer extends JetDeclarationImpl implements JetStatementExpression {
     public JetClassInitializer(@NotNull ASTNode node) {
         super(node);
     }
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClassObject.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClassObject.java
index 8bb61c8824e..14a3d34d1b6 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClassObject.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetClassObject.java
@@ -24,7 +24,7 @@ import org.jetbrains.jet.JetNodeTypes;
 /**
  * @author max
  */
-public class JetClassObject extends JetDeclaration implements JetStatementExpression {
+public class JetClassObject extends JetDeclarationImpl implements JetStatementExpression {
     public JetClassObject(@NotNull ASTNode node) {
         super(node);
     }
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDeclaration.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDeclaration.java
index 7caa013a3f4..a4df289944c 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDeclaration.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDeclaration.java
@@ -16,29 +16,17 @@
 
 package org.jetbrains.jet.lang.psi;
 
-import com.intellij.lang.ASTNode;
-import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.JetNodeTypes;
 import org.jetbrains.jet.lexer.JetToken;
 
 /**
- * @author max
+ * @author Nikolay Krasko
  */
-public abstract class JetDeclaration extends JetExpressionImpl implements JetModifierListOwner {
-    public JetDeclaration(@NotNull ASTNode node) {
-        super(node);
-    }
-
+public interface JetDeclaration extends JetExpression, JetModifierListOwner {
     @Override
     @Nullable
-    public JetModifierList getModifierList() {
-        return (JetModifierList) findChildByType(JetNodeTypes.MODIFIER_LIST);
-    }
+    JetModifierList getModifierList();
 
     @Override
-    public boolean hasModifier(JetToken modifier) {
-        JetModifierList modifierList = getModifierList();
-        return modifierList != null && modifierList.hasModifier(modifier);
-    }
+    boolean hasModifier(JetToken modifier);
 }
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDeclarationImpl.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDeclarationImpl.java
new file mode 100644
index 00000000000..4137aeed119
--- /dev/null
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetDeclarationImpl.java
@@ -0,0 +1,44 @@
+/*
+ * Copyright 2010-2012 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.
+ */
+
+package org.jetbrains.jet.lang.psi;
+
+import com.intellij.lang.ASTNode;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.annotations.Nullable;
+import org.jetbrains.jet.JetNodeTypes;
+import org.jetbrains.jet.lexer.JetToken;
+
+/**
+ * @author max
+ */
+abstract class JetDeclarationImpl extends JetExpressionImpl implements JetDeclaration {
+    public JetDeclarationImpl(@NotNull ASTNode node) {
+        super(node);
+    }
+
+    @Override
+    @Nullable
+    public JetModifierList getModifierList() {
+        return (JetModifierList) findChildByType(JetNodeTypes.MODIFIER_LIST);
+    }
+
+    @Override
+    public boolean hasModifier(JetToken modifier) {
+        JetModifierList modifierList = getModifierList();
+        return modifierList != null && modifierList.hasModifier(modifier);
+    }
+}
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetModifiableBlockHelper.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetModifiableBlockHelper.java
index 8133034391d..b5834b0a30e 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetModifiableBlockHelper.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetModifiableBlockHelper.java
@@ -30,7 +30,7 @@ public final class JetModifiableBlockHelper {
      * Tested in OutOfBlockModificationTest
      */
     public static boolean shouldChangeModificationCount(PsiElement place) {
-        JetDeclaration declaration = PsiTreeUtil.getParentOfType(place, JetDeclaration.class, true);
+        JetDeclaration declaration = PsiTreeUtil.getParentOfType(place, JetDeclarationImpl.class, true);
         if (declaration != null) {
             if (declaration instanceof JetNamedFunction) {
                 JetNamedFunction function = (JetNamedFunction) declaration;
@@ -61,7 +61,7 @@ public final class JetModifiableBlockHelper {
     }
 
     private static boolean takePartInDeclarationTypeInference(PsiElement place) {
-        JetDeclaration declaration = PsiTreeUtil.getParentOfType(place, JetDeclaration.class, true);
+        JetDeclaration declaration = PsiTreeUtil.getParentOfType(place, JetDeclarationImpl.class, true);
         if (declaration != null) {
             if (declaration instanceof JetNamedFunction) {
                 JetNamedFunction function = (JetNamedFunction) declaration;
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNamedDeclaration.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNamedDeclaration.java
index 8ce3419f837..b620b77a769 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNamedDeclaration.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetNamedDeclaration.java
@@ -29,7 +29,7 @@ import org.jetbrains.jet.lexer.JetTokens;
 /**
  * @author max
  */
-public abstract class JetNamedDeclaration extends JetDeclaration implements PsiNameIdentifierOwner, JetStatementExpression, JetNamed {
+public abstract class JetNamedDeclaration extends JetDeclarationImpl implements PsiNameIdentifierOwner, JetStatementExpression, JetNamed {
     public JetNamedDeclaration(@NotNull ASTNode node) {
         super(node);
     }
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetPropertyAccessor.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetPropertyAccessor.java
index f867190c51c..5b7ec411166 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetPropertyAccessor.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetPropertyAccessor.java
@@ -29,7 +29,7 @@ import java.util.List;
 /**
  * @author max
  */
-public class JetPropertyAccessor extends JetDeclaration implements JetDeclarationWithBody, JetModifierListOwner {
+public class JetPropertyAccessor extends JetDeclarationImpl implements JetDeclarationWithBody, JetModifierListOwner {
     public JetPropertyAccessor(@NotNull ASTNode node) {
         super(node);
     }
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetScript.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetScript.java
index dfb61ee3fa2..5aa0a7bff7b 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetScript.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetScript.java
@@ -25,7 +25,7 @@ import java.util.List;
 /**
  * @author Stepan Koltsov
  */
-public class JetScript extends JetDeclaration {
+public class JetScript extends JetDeclarationImpl {
 
     public JetScript(@NotNull ASTNode node) {
         super(node);
diff --git a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetSecondaryConstructor.java b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetSecondaryConstructor.java
index 7874086fba0..61bb31ee91b 100644
--- a/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetSecondaryConstructor.java
+++ b/compiler/frontend/src/org/jetbrains/jet/lang/psi/JetSecondaryConstructor.java
@@ -28,7 +28,7 @@ import java.util.List;
 /**
  * @author max
  */
-public class JetSecondaryConstructor extends JetDeclaration implements JetDeclarationWithBody, JetStatementExpression {
+public class JetSecondaryConstructor extends JetDeclarationImpl implements JetDeclarationWithBody, JetStatementExpression {
     public JetSecondaryConstructor(@NotNull ASTNode node) {
         super(node);
     }