diff --git a/idea/src/org/jetbrains/kotlin/idea/versions/KotlinAbiVersionIndex.kt b/idea/src/org/jetbrains/kotlin/idea/versions/KotlinAbiVersionIndex.kt
index 0e3cf9f5de5..685d3432a86 100644
--- a/idea/src/org/jetbrains/kotlin/idea/versions/KotlinAbiVersionIndex.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/versions/KotlinAbiVersionIndex.kt
@@ -14,139 +14,115 @@
  * limitations under the License.
  */
 
-package org.jetbrains.kotlin.idea.versions;
+package org.jetbrains.kotlin.idea.versions
 
-import com.google.common.collect.ImmutableSet;
-import com.google.common.collect.Maps;
-import com.intellij.openapi.diagnostic.Logger;
-import com.intellij.openapi.fileTypes.StdFileTypes;
-import com.intellij.openapi.util.Ref;
-import com.intellij.openapi.vfs.VirtualFile;
-import com.intellij.util.indexing.*;
-import com.intellij.util.io.ExternalIntegerKeyDescriptor;
-import com.intellij.util.io.KeyDescriptor;
-import org.jetbrains.annotations.NotNull;
-import org.jetbrains.kotlin.load.java.AbiVersionUtil;
-import org.jetbrains.org.objectweb.asm.AnnotationVisitor;
-import org.jetbrains.org.objectweb.asm.ClassReader;
-import org.jetbrains.org.objectweb.asm.ClassVisitor;
-import org.jetbrains.org.objectweb.asm.Opcodes;
+import com.google.common.collect.ImmutableSet
+import com.google.common.collect.Maps
+import com.intellij.openapi.diagnostic.Logger
+import com.intellij.openapi.fileTypes.StdFileTypes
+import com.intellij.openapi.util.Ref
+import com.intellij.openapi.vfs.VirtualFile
+import com.intellij.util.indexing.*
+import com.intellij.util.io.ExternalIntegerKeyDescriptor
+import com.intellij.util.io.KeyDescriptor
+import org.jetbrains.kotlin.load.java.AbiVersionUtil
+import org.jetbrains.org.objectweb.asm.AnnotationVisitor
+import org.jetbrains.org.objectweb.asm.ClassReader
+import org.jetbrains.org.objectweb.asm.ClassVisitor
+import org.jetbrains.org.objectweb.asm.Opcodes
 
-import java.util.Map;
-import java.util.Set;
-
-import static org.jetbrains.kotlin.codegen.AsmUtil.asmDescByFqNameWithoutInnerClasses;
-import static org.jetbrains.kotlin.load.java.JvmAnnotationNames.*;
+import org.jetbrains.kotlin.codegen.AsmUtil.asmDescByFqNameWithoutInnerClasses
+import org.jetbrains.kotlin.load.java.JvmAnnotationNames.*
 
 /**
  * Important! This is not a stub-based index. And it has its own version
  */
-public class KotlinAbiVersionIndex extends ScalarIndexExtension<Integer> constructor {
-    private static final Logger LOG = Logger.getInstance(KotlinAbiVersionIndex.class);
+public class KotlinAbiVersionIndex private constructor() : ScalarIndexExtension<Int>() {
 
-    public static final KotlinAbiVersionIndex INSTANCE = new KotlinAbiVersionIndex();
+    override fun getName(): ID<Int, Void> {
+        return NAME
+    }
 
-    private static final int VERSION = 1;
+    override fun getIndexer(): DataIndexer<Int, Void, FileContent> {
+        return INDEXER
+    }
 
-    private static final ID<Integer, Void> NAME = ID.create(KotlinAbiVersionIndex.class.getCanonicalName());
-    private static final ExternalIntegerKeyDescriptor KEY_DESCRIPTOR = new ExternalIntegerKeyDescriptor();
+    override fun getKeyDescriptor(): KeyDescriptor<Int> {
+        return KEY_DESCRIPTOR
+    }
 
-    private static final FileBasedIndex.InputFilter INPUT_FILTER = new FileBasedIndex.InputFilter() {
-        @Override
-        public boolean acceptInput(VirtualFile file) {
-            return file.getFileType() == StdFileTypes.CLASS;
+    override fun getInputFilter(): FileBasedIndex.InputFilter {
+        return INPUT_FILTER
+    }
+
+    override fun dependsOnFileContent(): Boolean {
+        return true
+    }
+
+    override fun getVersion(): Int {
+        return VERSION
+    }
+
+    companion object {
+        private val LOG = Logger.getInstance(javaClass<KotlinAbiVersionIndex>())
+
+        public val INSTANCE: KotlinAbiVersionIndex = KotlinAbiVersionIndex()
+
+        private val VERSION = 1
+
+        private val NAME = ID.create<Int, Void>(javaClass<KotlinAbiVersionIndex>().getCanonicalName())
+        private val KEY_DESCRIPTOR = ExternalIntegerKeyDescriptor()
+
+        private val INPUT_FILTER = object : FileBasedIndex.InputFilter {
+            override fun acceptInput(file: VirtualFile): Boolean {
+                return file.getFileType() == StdFileTypes.CLASS
+            }
         }
-    };
 
-    private static final DataIndexer<Integer, Void, FileContent> INDEXER = new DataIndexer<Integer, Void, FileContent>() {
-        @SuppressWarnings("deprecation")
-        private final Set<String> kotlinAnnotationsDesc = new ImmutableSet.Builder<String>()
-                .add(asmDescByFqNameWithoutInnerClasses(OLD_JET_CLASS_ANNOTATION))
-                .add(asmDescByFqNameWithoutInnerClasses(OLD_JET_PACKAGE_CLASS_ANNOTATION))
-                .add(asmDescByFqNameWithoutInnerClasses(OLD_KOTLIN_CLASS))
-                .add(asmDescByFqNameWithoutInnerClasses(OLD_KOTLIN_PACKAGE))
-                .add(asmDescByFqNameWithoutInnerClasses(KOTLIN_CLASS))
-                .add(asmDescByFqNameWithoutInnerClasses(KOTLIN_PACKAGE))
-                .build();
+        private val INDEXER = object : DataIndexer<Int, Void, FileContent> {
+            SuppressWarnings("deprecation")
+            private val kotlinAnnotationsDesc = ImmutableSet.Builder<String>().add(asmDescByFqNameWithoutInnerClasses(OLD_JET_CLASS_ANNOTATION)).add(asmDescByFqNameWithoutInnerClasses(OLD_JET_PACKAGE_CLASS_ANNOTATION)).add(asmDescByFqNameWithoutInnerClasses(OLD_KOTLIN_CLASS)).add(asmDescByFqNameWithoutInnerClasses(OLD_KOTLIN_PACKAGE)).add(asmDescByFqNameWithoutInnerClasses(KOTLIN_CLASS)).add(asmDescByFqNameWithoutInnerClasses(KOTLIN_PACKAGE)).build()
 
-        @NotNull
-        @Override
-        public Map<Integer, Void> map(FileContent inputData) {
-            final Map<Integer, Void> result = Maps.newHashMap();
-            final Ref<Boolean> annotationPresent = new Ref<Boolean>(false);
+            override fun map(inputData: FileContent): Map<Int, Void> {
+                val result = Maps.newHashMap<Int, Void>()
+                val annotationPresent = Ref(false)
 
-            try {
-                ClassReader classReader = new ClassReader(inputData.getContent());
-                classReader.accept(new ClassVisitor(Opcodes.ASM5) {
-                    @Override
-                    public AnnotationVisitor visitAnnotation(String desc, boolean visible) {
-                        if (!kotlinAnnotationsDesc.contains(desc)) {
-                            return null;
-                        }
-                        annotationPresent.set(true);
-                        return new AnnotationVisitor(Opcodes.ASM5) {
-                            @Override
-                            public void visit(String name, Object value) {
-                                if (ABI_VERSION_FIELD_NAME.equals(name)) {
-                                    if (value instanceof Integer) {
-                                        Integer abiVersion = (Integer) value;
-                                        result.put(abiVersion, null);
-                                    }
-                                    else {
-                                        // Version is set to something weird
-                                        result.put(AbiVersionUtil.INVALID_VERSION, null);
+                try {
+                    val classReader = ClassReader(inputData.getContent())
+                    classReader.accept(object : ClassVisitor(Opcodes.ASM5) {
+                        override fun visitAnnotation(desc: String, visible: Boolean): AnnotationVisitor? {
+                            if (!kotlinAnnotationsDesc.contains(desc)) {
+                                return null
+                            }
+                            annotationPresent.set(true)
+                            return object : AnnotationVisitor(Opcodes.ASM5) {
+                                override fun visit(name: String, value: Any) {
+                                    if (ABI_VERSION_FIELD_NAME == name) {
+                                        if (value is Int) {
+                                            result.put(value, null)
+                                        }
+                                        else {
+                                            // Version is set to something weird
+                                            result.put(AbiVersionUtil.INVALID_VERSION, null)
+                                        }
                                     }
                                 }
                             }
-                        };
-                    }
-                }, ClassReader.SKIP_CODE | ClassReader.SKIP_DEBUG | ClassReader.SKIP_FRAMES);
-            }
-            catch (Throwable e) {
-                LOG.warn("Could not index ABI version for file " + inputData.getFile() + ": " + e.getMessage());
-            }
+                        }
+                    }, ClassReader.SKIP_CODE or ClassReader.SKIP_DEBUG or ClassReader.SKIP_FRAMES)
+                }
+                catch (e: Throwable) {
+                    LOG.warn("Could not index ABI version for file " + inputData.getFile() + ": " + e.getMessage())
+                }
 
-            if (annotationPresent.get() && result.isEmpty()) {
-                // No version at all: the class is too old
-                result.put(AbiVersionUtil.INVALID_VERSION, null);
-            }
 
-            return result;
+                if (annotationPresent.get() && result.isEmpty()) {
+                    // No version at all: the class is too old
+                    result.put(AbiVersionUtil.INVALID_VERSION, null)
+                }
+
+                return result
+            }
         }
-    };
-
-    private KotlinAbiVersionIndex() {
-    }
-
-    @NotNull
-    @Override
-    public ID<Integer, Void> getName() {
-        return NAME;
-    }
-
-    @NotNull
-    @Override
-    public DataIndexer<Integer, Void, FileContent> getIndexer() {
-        return INDEXER;
-    }
-
-    @Override
-    public KeyDescriptor<Integer> getKeyDescriptor() {
-        return KEY_DESCRIPTOR;
-    }
-
-    @Override
-    public FileBasedIndex.InputFilter getInputFilter() {
-        return INPUT_FILTER;
-    }
-
-    @Override
-    public boolean dependsOnFileContent() {
-        return true;
-    }
-
-    @Override
-    public int getVersion() {
-        return VERSION;
     }
 }