diff --git a/src/org/jetbrains/jet/j2k/ast/IsOperator.java b/src/org/jetbrains/jet/j2k/ast/IsOperator.java
deleted file mode 100644
index 79262f14871..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/IsOperator.java
+++ /dev/null
@@ -1,38 +0,0 @@
-/*
- * 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.j2k.ast;
-
-import org.jetbrains.annotations.NotNull;
-
-/**
- * @author ignatov
- */
-public class IsOperator extends Expression {
-    private final Expression myExpression;
-    private final Element myTypeElement;
-
-    public IsOperator(Expression expression, Element typeElement) {
-        myExpression = expression;
-        myTypeElement = typeElement;
-    }
-
-    @NotNull
-    @Override
-    public String toKotlin() {
-        return "(" + myExpression.toKotlin() + SPACE + "is" + SPACE + myTypeElement.toKotlin() + ")";
-    }
-}
diff --git a/src/org/jetbrains/jet/j2k/ast/IsOperator.kt b/src/org/jetbrains/jet/j2k/ast/IsOperator.kt
new file mode 100644
index 00000000000..cb853651339
--- /dev/null
+++ b/src/org/jetbrains/jet/j2k/ast/IsOperator.kt
@@ -0,0 +1,8 @@
+package org.jetbrains.jet.j2k.ast
+
+
+public open class IsOperator(val expression: Expression, val typeElement: TypeElement): Expression() {
+    public override fun toKotlin(): String {
+        return expression.toKotlin() + " is " + typeElement.`type`.convertedToNotNull().toKotlin()
+    }
+}
diff --git a/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java b/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
index 2494e56d499..64262828ec8 100644
--- a/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
+++ b/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
@@ -22,6 +22,7 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.annotations.Nullable;
 import org.jetbrains.jet.j2k.Converter;
 import org.jetbrains.jet.j2k.ast.*;
+import org.jetbrains.jet.j2k.ast.types.EmptyType;
 import org.jetbrains.jet.j2k.ast.types.Type;
 import org.jetbrains.jet.lang.types.expressions.OperatorConventions;
 
@@ -189,9 +190,10 @@ public class ExpressionVisitor extends StatementVisitor {
     @Override
     public void visitInstanceOfExpression(@NotNull PsiInstanceOfExpression expression) {
         super.visitInstanceOfExpression(expression);
+        PsiTypeElement checkType = expression.getCheckType();
         myResult = new IsOperator(
                 getConverter().expressionToExpression(expression.getOperand()),
-                getConverter().elementToElement(expression.getCheckType()));
+                new TypeElement(checkType == null ? new EmptyType() : myConverter.typeToType(checkType.getType())));
     }
 
     @Override
diff --git a/tests/testData/ast/isOperator/expression/complicatedExpression.kt b/tests/testData/ast/isOperator/expression/complicatedExpression.kt
index 3105c369fbe..1cf2e9ebc79 100644
--- a/tests/testData/ast/isOperator/expression/complicatedExpression.kt
+++ b/tests/testData/ast/isOperator/expression/complicatedExpression.kt
@@ -1 +1 @@
-(c.getType().getName() is String?)
\ No newline at end of file
+c.getType().getName() is String
\ No newline at end of file
diff --git a/tests/testData/ast/isOperator/expression/simpleReference.kt b/tests/testData/ast/isOperator/expression/simpleReference.kt
index 544cd7f6728..7ccaa0c9744 100644
--- a/tests/testData/ast/isOperator/expression/simpleReference.kt
+++ b/tests/testData/ast/isOperator/expression/simpleReference.kt
@@ -1 +1 @@
-(a is String?)
\ No newline at end of file
+a is String
\ No newline at end of file