diff --git a/idea/src/org/jetbrains/kotlin/idea/configuration/ConfigureKotlinInProjectUtils.kt b/idea/src/org/jetbrains/kotlin/idea/configuration/ConfigureKotlinInProjectUtils.kt
index a27b589919b..f1560a48ab5 100644
--- a/idea/src/org/jetbrains/kotlin/idea/configuration/ConfigureKotlinInProjectUtils.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/configuration/ConfigureKotlinInProjectUtils.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
+ * Copyright 2010-2016 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.
@@ -27,7 +27,7 @@ import com.intellij.psi.search.GlobalSearchScope
 import org.jetbrains.kotlin.idea.KotlinFileType
 import org.jetbrains.kotlin.idea.configuration.ui.notifications.ConfigureKotlinNotification
 import org.jetbrains.kotlin.idea.util.projectStructure.allModules
-import org.jetbrains.kotlin.idea.versions.getKotlinRuntimeMarkerClass
+import org.jetbrains.kotlin.idea.versions.hasKotlinRuntimeMarkerClass
 import org.jetbrains.kotlin.utils.ifEmpty
 
 data class RepositoryDescription(val id: String, val name: String, val url: String, val isSnapshot: Boolean)
@@ -125,7 +125,7 @@ fun getNonConfiguredModules(project: Project, excludeModules: Collection<Module>
 
 fun hasKotlinRuntimeInScope(module: Module): Boolean {
     val scope = module.getModuleWithDependenciesAndLibrariesScope(hasKotlinFilesOnlyInTests(module))
-    return getKotlinRuntimeMarkerClass(module.project, scope) != null
+    return hasKotlinRuntimeMarkerClass(module.project, scope)
 }
 
 fun hasKotlinFilesOnlyInTests(module: Module): Boolean {
diff --git a/idea/src/org/jetbrains/kotlin/idea/configuration/KotlinJavaModuleConfigurator.java b/idea/src/org/jetbrains/kotlin/idea/configuration/KotlinJavaModuleConfigurator.java
index 38a498f2a40..e829429daeb 100644
--- a/idea/src/org/jetbrains/kotlin/idea/configuration/KotlinJavaModuleConfigurator.java
+++ b/idea/src/org/jetbrains/kotlin/idea/configuration/KotlinJavaModuleConfigurator.java
@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
+ * Copyright 2010-2016 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.
@@ -107,7 +107,7 @@ public class KotlinJavaModuleConfigurator extends KotlinWithLibraryConfigurator
         }
 
         LibraryScope scope = new LibraryScope(project, library);
-        return KotlinRuntimeLibraryUtilKt.getKotlinRuntimeMarkerClass(project, scope) != null;
+        return KotlinRuntimeLibraryUtilKt.hasKotlinRuntimeMarkerClass(project, scope);
     }
 
     KotlinJavaModuleConfigurator() {
diff --git a/idea/src/org/jetbrains/kotlin/idea/versions/KotlinRuntimeLibraryUtil.kt b/idea/src/org/jetbrains/kotlin/idea/versions/KotlinRuntimeLibraryUtil.kt
index 4e80a104d07..4b6b7849061 100644
--- a/idea/src/org/jetbrains/kotlin/idea/versions/KotlinRuntimeLibraryUtil.kt
+++ b/idea/src/org/jetbrains/kotlin/idea/versions/KotlinRuntimeLibraryUtil.kt
@@ -1,5 +1,5 @@
 /*
- * Copyright 2010-2015 JetBrains s.r.o.
+ * Copyright 2010-2016 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.
@@ -32,13 +32,13 @@ import com.intellij.openapi.util.text.StringUtil
 import com.intellij.openapi.vfs.JarFileSystem
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.JavaPsiFacade
-import com.intellij.psi.PsiClass
 import com.intellij.psi.search.GlobalSearchScope
 import com.intellij.util.PathUtil.getLocalFile
 import com.intellij.util.PathUtil.getLocalPath
 import com.intellij.util.containers.MultiMap
 import com.intellij.util.indexing.FileBasedIndex
 import com.intellij.util.indexing.ScalarIndexExtension
+import org.jetbrains.kotlin.builtins.KotlinBuiltIns
 import org.jetbrains.kotlin.idea.KotlinPluginUtil
 import org.jetbrains.kotlin.idea.configuration.KotlinJavaModuleConfigurator
 import org.jetbrains.kotlin.idea.configuration.KotlinJsModuleConfigurator
@@ -47,7 +47,9 @@ import org.jetbrains.kotlin.idea.configuration.getConfiguratorByName
 import org.jetbrains.kotlin.idea.framework.*
 import org.jetbrains.kotlin.idea.util.application.runReadAction
 import org.jetbrains.kotlin.idea.util.runWithAlternativeResolveEnabled
+import org.jetbrains.kotlin.idea.vfilefinder.JsVirtualFileFinderFactory
 import org.jetbrains.kotlin.load.kotlin.JvmMetadataVersion
+import org.jetbrains.kotlin.name.ClassId
 import org.jetbrains.kotlin.serialization.deserialization.BinaryVersion
 import org.jetbrains.kotlin.utils.JsBinaryVersion
 import org.jetbrains.kotlin.utils.KotlinJavascriptMetadataUtils
@@ -256,11 +258,16 @@ fun showRuntimeJarNotFoundDialog(project: Project, jarName: String) {
                              "No Runtime Found")
 }
 
-fun getKotlinRuntimeMarkerClass(project: Project, scope: GlobalSearchScope): PsiClass? {
+fun hasKotlinRuntimeMarkerClass(project: Project, scope: GlobalSearchScope): Boolean {
     return runReadAction {
         project.runWithAlternativeResolveEnabled {
-            JavaPsiFacade.getInstance(project).findClass("kotlin.Unit", scope)
+            getKotlinJvmRuntimeMarkerClass(project, scope) != null || getKotlinJsRuntimeMarkerClass(project, scope) != null
         }
     }
 }
 
+private fun getKotlinJvmRuntimeMarkerClass(project: Project, scope: GlobalSearchScope) =
+        JavaPsiFacade.getInstance(project).findClass(KotlinBuiltIns.FQ_NAMES.unit.asString(), scope)
+
+private fun getKotlinJsRuntimeMarkerClass(project: Project, scope: GlobalSearchScope) =
+        JsVirtualFileFinderFactory.SERVICE.getInstance(project).create(scope).findVirtualFileWithHeader(ClassId.topLevel(KotlinBuiltIns.FQ_NAMES.unit.toSafe()))
diff --git a/jslib_files.xml b/jslib_files.xml
index 6d4d47e7ec2..074827cbc11 100644
--- a/jslib_files.xml
+++ b/jslib_files.xml
@@ -18,6 +18,7 @@
         <fileset dir="${basedir}/core/builtins/src">
             <include name="kotlin/reflect/**/*.kt"/>
             <include name="kotlin/annotation/Annotations.kt"/>
+            <include name="kotlin/Unit.kt"/>
         </fileset>
 
         <fileset dir="${basedir}/libraries/kotlin.test/shared">