diff --git a/idea/src/META-INF/plugin.xml b/idea/src/META-INF/plugin.xml
index 618bf01be3d..091439bdeef 100644
--- a/idea/src/META-INF/plugin.xml
+++ b/idea/src/META-INF/plugin.xml
@@ -265,6 +265,7 @@
     <stubIndex implementation="org.jetbrains.jet.plugin.stubindex.JetTopLevelShortObjectNameIndex"/>
 
     <fileBasedIndex implementation="org.jetbrains.jet.plugin.versions.KotlinAbiVersionIndex"/>
+    <fileBasedIndex implementation="org.jetbrains.jet.plugin.vfilefinder.KotlinClassFileIndex"/>
 
     <contentBasedClassFileProcessor implementation="org.jetbrains.jet.plugin.libraries.JetContentBasedFileSubstitutor"/>
     <psi.clsCustomNavigationPolicy implementation="org.jetbrains.jet.plugin.libraries.JetClsNavigationPolicy"/>
diff --git a/idea/src/org/jetbrains/jet/plugin/vfilefinder/KotlinClassFileIndex.java b/idea/src/org/jetbrains/jet/plugin/vfilefinder/KotlinClassFileIndex.java
new file mode 100644
index 00000000000..bf178ed0013
--- /dev/null
+++ b/idea/src/org/jetbrains/jet/plugin/vfilefinder/KotlinClassFileIndex.java
@@ -0,0 +1,105 @@
+package org.jetbrains.jet.plugin.vfilefinder;
+
+import com.intellij.openapi.diagnostic.Logger;
+import com.intellij.openapi.fileTypes.StdFileTypes;
+import com.intellij.openapi.vfs.VirtualFile;
+import com.intellij.util.indexing.*;
+import com.intellij.util.io.KeyDescriptor;
+import org.jetbrains.annotations.NotNull;
+import org.jetbrains.jet.lang.resolve.java.resolver.KotlinClassFileHeader;
+import org.jetbrains.jet.lang.resolve.name.FqName;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOException;
+import java.util.Collections;
+import java.util.HashMap;
+import java.util.Map;
+
+public final class KotlinClassFileIndex extends ScalarIndexExtension<FqName> {
+
+    private static final Logger LOG = Logger.getInstance(KotlinClassFileIndex.class);
+    private static final int VERSION = 1;
+    public static final ID<FqName, Void> KEY = ID.create(KotlinClassFileIndex.class.getCanonicalName());
+
+    private static final KeyDescriptor<FqName> KEY_DESCRIPTOR = new KeyDescriptor<FqName>() {
+        @Override
+        public void save(DataOutput out, FqName value) throws IOException {
+            out.writeUTF(value.asString());
+        }
+
+        @Override
+        public FqName read(DataInput in) throws IOException {
+            return new FqName(in.readUTF());
+        }
+
+        @Override
+        public int getHashCode(FqName value) {
+            return value.asString().hashCode();
+        }
+
+        @Override
+        public boolean isEqual(FqName val1, FqName val2) {
+            if (val1 == null) {
+                return val2 == null;
+            }
+            return val1.equals(val1);
+        }
+    };
+
+    private static final FileBasedIndex.InputFilter INPUT_FILTER = new FileBasedIndex.InputFilter() {
+        @Override
+        public boolean acceptInput(VirtualFile file) {
+            return file.getFileType() == StdFileTypes.CLASS;
+        }
+    };
+    public static final DataIndexer<FqName, Void, FileContent> INDEXER = new DataIndexer<FqName, Void, FileContent>() {
+        @NotNull
+        @Override
+        public Map<FqName, Void> map(FileContent inputData) {
+            try {
+                KotlinClassFileHeader header = KotlinClassFileHeader.readKotlinHeaderFromClassFile(inputData.getFile());
+                if (header.isKotlinCompiledFile()) {
+                    FqName fqName = header.getJvmClassName().getFqName();
+                    return Collections.singletonMap(fqName, null);
+                }
+            }
+            catch (Throwable e) {
+                LOG.error("Error while indexing file " + inputData.getFileName(), e);
+            }
+            return Collections.emptyMap();
+        }
+    };
+
+    @NotNull
+    @Override
+    public ID<FqName, Void> getName() {
+        return KEY;
+    }
+
+    @NotNull
+    @Override
+    public DataIndexer<FqName, Void, FileContent> getIndexer() {
+        return INDEXER;
+    }
+
+    @Override
+    public KeyDescriptor<FqName> getKeyDescriptor() {
+        return KEY_DESCRIPTOR;
+    }
+
+    @Override
+    public FileBasedIndex.InputFilter getInputFilter() {
+        return INPUT_FILTER;
+    }
+
+    @Override
+    public boolean dependsOnFileContent() {
+        return true;
+    }
+
+    @Override
+    public int getVersion() {
+        return VERSION;
+    }
+}