diff --git a/core/descriptors/src/org/jetbrains/jet/lang/types/lang/BuiltInsSerializationUtil.java b/core/descriptors/src/org/jetbrains/jet/lang/types/lang/BuiltInsSerializationUtil.java
deleted file mode 100644
index 3b4953f268d..00000000000
--- a/core/descriptors/src/org/jetbrains/jet/lang/types/lang/BuiltInsSerializationUtil.java
+++ /dev/null
@@ -1,82 +0,0 @@
-/*
- * Copyright 2010-2013 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.types.lang;
-
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.annotations.Nullable;
-import org.jetbrains.jet.lang.resolve.name.ClassId;
-import org.jetbrains.jet.lang.resolve.name.FqName;
-import org.jetbrains.jet.lang.resolve.name.FqNameUnsafe;
-import org.jetbrains.jet.lang.resolve.name.Name;
-
-import java.util.ArrayList;
-import java.util.List;
-
-import static org.jetbrains.jet.lang.resolve.name.SpecialNames.isClassObjectName;
-
-public class BuiltInsSerializationUtil {
-    private static final String CLASS_METADATA_FILE_EXTENSION = "kotlin_class";
-    private static final String PACKAGE_FILE_NAME = ".kotlin_package";
-    private static final String NAME_TABLE_FILE_NAME = ".kotlin_name_table";
-    private static final String CLASS_NAMES_FILE_NAME = ".kotlin_class_names";
-    private static final String CLASS_OBJECT_NAME = "object";
-
-    private BuiltInsSerializationUtil() {
-    }
-
-    @Nullable
-    private static String relativeClassNameToFilePath(@NotNull FqNameUnsafe className) {
-        List<Name> segments = className.pathSegments();
-        List<String> correctedSegments = new ArrayList<String>(segments.size());
-        for (Name segment : segments) {
-            if (isClassObjectName(segment)) {
-                correctedSegments.add(CLASS_OBJECT_NAME);
-            }
-            else if (!segment.isSpecial()) {
-                correctedSegments.add(segment.getIdentifier());
-            }
-            else return null;
-        }
-        return FqName.fromSegments(correctedSegments).asString();
-    }
-
-    @Nullable
-    public static String getClassMetadataPath(@NotNull ClassId classId) {
-        String filePath = relativeClassNameToFilePath(classId.getRelativeClassName());
-        if (filePath == null) return null;
-        return packageFqNameToPath(classId.getPackageFqName()) + "/" + filePath + "." + CLASS_METADATA_FILE_EXTENSION;
-    }
-
-    @NotNull
-    public static String getPackageFilePath(@NotNull FqName fqName) {
-        return packageFqNameToPath(fqName) + "/" + PACKAGE_FILE_NAME;
-    }
-
-    @NotNull
-    public static String getNameTableFilePath(@NotNull FqName fqName) {
-        return packageFqNameToPath(fqName) + "/" + NAME_TABLE_FILE_NAME;
-    }
-
-    @NotNull
-    public static String getClassNamesFilePath(@NotNull FqName fqName) {
-        return packageFqNameToPath(fqName) + "/" + CLASS_NAMES_FILE_NAME;
-    }
-
-    private static String packageFqNameToPath(FqName fqName) {
-        return fqName.asString().replace('.', '/');
-    }
-}
diff --git a/core/descriptors/src/org/jetbrains/jet/lang/types/lang/BuiltInsSerializationUtil.kt b/core/descriptors/src/org/jetbrains/jet/lang/types/lang/BuiltInsSerializationUtil.kt
new file mode 100644
index 00000000000..60ccab47890
--- /dev/null
+++ b/core/descriptors/src/org/jetbrains/jet/lang/types/lang/BuiltInsSerializationUtil.kt
@@ -0,0 +1,56 @@
+/*
+ * Copyright 2010-2014 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.types.lang
+
+import org.jetbrains.jet.lang.resolve.name.*
+import kotlin.platform.platformStatic
+
+public object BuiltInsSerializationUtil {
+    private val CLASS_METADATA_FILE_EXTENSION = "kotlin_class"
+    private val PACKAGE_FILE_NAME = ".kotlin_package"
+    private val NAME_TABLE_FILE_NAME = ".kotlin_name_table"
+    private val CLASS_NAMES_FILE_NAME = ".kotlin_class_names"
+    private val CLASS_OBJECT_NAME = "object"
+
+    private fun relativeClassNameToFilePath(className: FqNameUnsafe): String? {
+        return FqName.fromSegments(className.pathSegments().map { segment ->
+            when {
+                SpecialNames.isClassObjectName(segment) -> CLASS_OBJECT_NAME
+                !segment.isSpecial() -> segment.getIdentifier()
+                else -> return null
+            }
+        }).asString()
+    }
+
+    platformStatic public fun getClassMetadataPath(classId: ClassId): String? {
+        val filePath = relativeClassNameToFilePath(classId.getRelativeClassName())
+        if (filePath == null) return null
+        return packageFqNameToPath(classId.getPackageFqName()) + "/" + filePath + "." + CLASS_METADATA_FILE_EXTENSION
+    }
+
+    platformStatic public fun getPackageFilePath(fqName: FqName): String =
+            packageFqNameToPath(fqName) + "/" + PACKAGE_FILE_NAME
+
+    platformStatic public fun getNameTableFilePath(fqName: FqName): String =
+            packageFqNameToPath(fqName) + "/" + NAME_TABLE_FILE_NAME
+
+    platformStatic public fun getClassNamesFilePath(fqName: FqName): String =
+            packageFqNameToPath(fqName) + "/" + CLASS_NAMES_FILE_NAME
+
+    private fun packageFqNameToPath(fqName: FqName): String =
+            fqName.asString().replace('.', '/')
+}