diff --git a/src/org/jetbrains/jet/j2k/ast/BinaryExpression.java b/src/org/jetbrains/jet/j2k/ast/BinaryExpression.java
deleted file mode 100644
index 42c7f8773cf..00000000000
--- a/src/org/jetbrains/jet/j2k/ast/BinaryExpression.java
+++ /dev/null
@@ -1,51 +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;
-import org.jetbrains.jet.j2k.util.AstUtil;
-
-import java.util.Arrays;
-import java.util.List;
-
-/**
- * @author ignatov
- */
-public class BinaryExpression extends Expression {
-    private final Expression myLeft;
-    private final Expression myRight;
-    private final String myOp;
-    private final List<String> myConversions;
-
-    public BinaryExpression(Expression left, Expression right, String op) {
-        this(left, right, op, Arrays.asList("", ""));
-    }
-
-    public BinaryExpression(Expression left, Expression right, String op, List<String> conversions) {
-        myLeft = left;
-        myRight = right;
-        myOp = op;
-        myConversions = conversions;
-    }
-
-    @NotNull
-    @Override
-    public String toKotlin() {
-        List<String> expressionsWithConversions = AstUtil.applyConversions(AstUtil.nodesToKotlin(Arrays.asList(myLeft, myRight)), myConversions);
-        return AstUtil.join(expressionsWithConversions, SPACE + myOp + SPACE);
-    }
-}
diff --git a/src/org/jetbrains/jet/j2k/ast/BinaryExpression.kt b/src/org/jetbrains/jet/j2k/ast/BinaryExpression.kt
new file mode 100644
index 00000000000..ead17689913
--- /dev/null
+++ b/src/org/jetbrains/jet/j2k/ast/BinaryExpression.kt
@@ -0,0 +1,9 @@
+package org.jetbrains.jet.j2k.ast
+
+import org.jetbrains.jet.j2k.util.AstUtil
+import java.util.Arrays
+import java.util.List
+
+public open class BinaryExpression(val left: Expression, val right: Expression, val op: String): Expression() {
+    public override fun toKotlin(): String = left.toKotlin() + " " + op + " " + right.toKotlin()
+}
diff --git a/src/org/jetbrains/jet/j2k/ast/MethodCallExpression.java b/src/org/jetbrains/jet/j2k/ast/MethodCallExpression.java
index 8c162ae07eb..cb541679f98 100644
--- a/src/org/jetbrains/jet/j2k/ast/MethodCallExpression.java
+++ b/src/org/jetbrains/jet/j2k/ast/MethodCallExpression.java
@@ -46,7 +46,7 @@ public class MethodCallExpression extends Expression {
 
     @Override
     public boolean isNullable() {
-        return myIsResultNullable;
+        return myMethodCall.isNullable() || myIsResultNullable;
     }
 
     @NotNull
diff --git a/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java b/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
index e39b9ffc450..00323b9c8f8 100644
--- a/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
+++ b/src/org/jetbrains/jet/j2k/visitors/ExpressionVisitor.java
@@ -150,10 +150,9 @@ public class ExpressionVisitor extends StatementVisitor {
         else {
             myResult =
                     new BinaryExpression(
-                            getConverter().expressionToExpression(expression.getLOperand()),
-                            getConverter().expressionToExpression(expression.getROperand()),
-                            getOperatorString(expression.getOperationSign().getTokenType()),
-                            getConverter().createConversions(expression, PsiType.BOOLEAN)
+                            getConverter().expressionToExpression(expression.getLOperand(), expression.getType()),
+                            getConverter().expressionToExpression(expression.getROperand(), expression.getType()),
+                            getOperatorString(expression.getOperationSign().getTokenType())
                     );
         }
     }
diff --git a/tests/testData/ast/issues/file/kt-852.kt b/tests/testData/ast/issues/file/kt-852.kt
index 67038cd5c1a..5108a7b821d 100644
--- a/tests/testData/ast/issues/file/kt-852.kt
+++ b/tests/testData/ast/issues/file/kt-852.kt
@@ -4,7 +4,7 @@ open fun test() : String? {
 var s1 : String? = ""
 var s2 : String? = ""
 var s3 : String? = ""
-if ((s1?.isEmpty()).sure() && (s2?.isEmpty()).sure())
+if (s1?.isEmpty()!! && s2?.isEmpty()!!)
 return "OK"
 if ((s1?.isEmpty()).sure() && (s2?.isEmpty()).sure() && (s3?.isEmpty()).sure())
 return "OOOK"