diff --git a/j2k/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java b/j2k/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
index a3674f074b2..24491c56ffe 100644
--- a/j2k/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
+++ b/j2k/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
@@ -192,9 +192,10 @@ public class ExpressionVisitor extends StatementVisitor {
     @Override
     public void visitInstanceOfExpression(@NotNull PsiInstanceOfExpression expression) {
         super.visitInstanceOfExpression(expression);
-        myResult = new IsOperator(
-                getConverter().expressionToExpression(expression.getOperand()),
-                getConverter().elementToElement(expression.getCheckType()));
+
+        TypeElement typeElement = (TypeElement) getConverter().elementToElement(expression.getCheckType());
+        typeElement.getMyType().convertedToNotNull();
+        myResult = new IsOperator(getConverter().expressionToExpression(expression.getOperand()), typeElement);
     }
 
     @Override
diff --git a/j2k/tests/testData/ast/isOperator/expression/complicatedExpression.kt b/j2k/tests/testData/ast/isOperator/expression/complicatedExpression.kt
index 3105c369fbe..5dba2fe4d5d 100644
--- a/j2k/tests/testData/ast/isOperator/expression/complicatedExpression.kt
+++ b/j2k/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/j2k/tests/testData/ast/isOperator/expression/simpleReference.kt b/j2k/tests/testData/ast/isOperator/expression/simpleReference.kt
index 544cd7f6728..3c65a411cc1 100644
--- a/j2k/tests/testData/ast/isOperator/expression/simpleReference.kt
+++ b/j2k/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