diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/resolve/JsProjectDetector.kt b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/resolve/JsProjectDetector.kt
deleted file mode 100644
index cfe9795dedc..00000000000
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/resolve/JsProjectDetector.kt
+++ /dev/null
@@ -1,36 +0,0 @@
-/*
- * Copyright 2010-2015 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.kotlin.idea.caches.resolve
-
-import com.intellij.openapi.module.ModuleManager
-import com.intellij.openapi.project.Project
-import com.intellij.openapi.roots.ProjectRootModificationTracker
-import com.intellij.psi.util.CachedValueProvider
-import com.intellij.psi.util.CachedValuesManager
-import org.jetbrains.kotlin.idea.project.TargetPlatformDetector
-import org.jetbrains.kotlin.js.resolve.JsPlatform
-
-//TODO: this should go away to support cross-platform projects
-object JsProjectDetector {
-    @JvmStatic
-    fun isJsProject(project: Project): Boolean {
-        return CachedValuesManager.getManager(project).getCachedValue(project) {
-            val result = ModuleManager.getInstance(project).modules.any { TargetPlatformDetector.getPlatform(it) == JsPlatform }
-            CachedValueProvider.Result(result, ProjectRootModificationTracker.getInstance(project))
-        }
-    }
-}
diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/KotlinSourceFilterScope.kt b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/KotlinSourceFilterScope.kt
index 28e155c6e22..d69d5d8a6ff 100644
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/KotlinSourceFilterScope.kt
+++ b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/stubindex/KotlinSourceFilterScope.kt
@@ -35,16 +35,13 @@ class KotlinSourceFilterScope private constructor(
 
     private val index = ProjectRootManager.getInstance(project).fileIndex
 
-    //NOTE: avoid recomputing in potentially bottleneck 'contains' method
-    private val isJsProjectRef = Ref<Boolean?>(null)
-
     override fun getProject() = project
 
     override fun contains(file: VirtualFile): Boolean {
         if (!super.contains(file)) return false
 
         return ProjectRootsUtil.isInContent(
-                project, file, includeProjectSourceFiles, includeLibrarySourceFiles, includeClassFiles, includeScriptDependencies, index, isJsProjectRef
+                project, file, includeProjectSourceFiles, includeLibrarySourceFiles, includeClassFiles, includeScriptDependencies, index
         )
     }
 
diff --git a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/util/ProjectRootsUtil.kt b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/util/ProjectRootsUtil.kt
index a8796046950..c54aa55ffdd 100644
--- a/idea/idea-analysis/src/org/jetbrains/kotlin/idea/util/ProjectRootsUtil.kt
+++ b/idea/idea-analysis/src/org/jetbrains/kotlin/idea/util/ProjectRootsUtil.kt
@@ -28,15 +28,14 @@ import com.intellij.openapi.roots.FileIndex
 import com.intellij.openapi.roots.ModuleRootManager
 import com.intellij.openapi.roots.ProjectFileIndex
 import com.intellij.openapi.roots.ProjectRootManager
-import com.intellij.openapi.util.Ref
 import com.intellij.openapi.vfs.VirtualFile
 import com.intellij.psi.PsiDirectory
 import com.intellij.psi.PsiElement
 import com.intellij.psi.PsiFileSystemItem
 import org.jetbrains.kotlin.idea.KotlinModuleFileType
-import org.jetbrains.kotlin.idea.caches.resolve.JsProjectDetector
 import org.jetbrains.kotlin.idea.core.script.ScriptDependenciesManager
 import org.jetbrains.kotlin.idea.decompiler.builtIns.KotlinBuiltInFileType
+import org.jetbrains.kotlin.idea.decompiler.js.KotlinJavaScriptMetaFileType
 import org.jetbrains.kotlin.idea.util.application.runReadAction
 
 abstract class KotlinBinaryExtension(val fileType: FileType) {
@@ -53,6 +52,7 @@ abstract class KotlinBinaryExtension(val fileType: FileType) {
 class JavaClassBinary: KotlinBinaryExtension(JavaClassFileType.INSTANCE)
 class KotlinBuiltInBinary: KotlinBinaryExtension(KotlinBuiltInFileType)
 class KotlinModuleBinary: KotlinBinaryExtension(KotlinModuleFileType.INSTANCE)
+class KotlinJsMetaBinary: KotlinBinaryExtension(KotlinJavaScriptMetaFileType)
 
 fun FileType.isKotlinBinary(): Boolean = this in KotlinBinaryExtension.kotlinBinaries
 
@@ -69,8 +69,7 @@ object ProjectRootsUtil {
     @JvmStatic fun isInContent(project: Project, file: VirtualFile, includeProjectSource: Boolean,
                                includeLibrarySource: Boolean, includeLibraryClasses: Boolean,
                                includeScriptDependencies: Boolean,
-                               fileIndex: ProjectFileIndex = ProjectFileIndex.SERVICE.getInstance(project),
-                               isJsProjectRef: Ref<Boolean?>? = null): Boolean {
+                               fileIndex: ProjectFileIndex = ProjectFileIndex.SERVICE.getInstance(project)): Boolean {
 
         if (includeProjectSource && fileIndex.isInSourceContentWithoutInjected(file)) return true
 
@@ -92,15 +91,6 @@ object ProjectRootsUtil {
             if (scriptConfigurationManager?.getAllLibrarySourcesScope()?.contains(file) == true) return true
         }
 
-        if ((includeLibraryClasses && fileIndex.isInLibraryClasses(file)) ||
-            (includeLibrarySource && fileIndex.isInLibrarySource(file))) {
-
-            //NOTE: avoid computing isJsProject if redundant
-            val isJsProject = isJsProjectRef?.get() ?: JsProjectDetector.isJsProject(project)
-            isJsProjectRef?.set(isJsProject)
-            return isJsProject
-        }
-
         return false
     }
 
diff --git a/idea/src/META-INF/plugin.xml b/idea/src/META-INF/plugin.xml
index 780d440cd4e..81ac1aa421d 100644
--- a/idea/src/META-INF/plugin.xml
+++ b/idea/src/META-INF/plugin.xml
@@ -2726,6 +2726,7 @@
     <binaryExtension implementation="org.jetbrains.kotlin.idea.util.JavaClassBinary"/>
     <binaryExtension implementation="org.jetbrains.kotlin.idea.util.KotlinBuiltInBinary"/>
     <binaryExtension implementation="org.jetbrains.kotlin.idea.util.KotlinModuleBinary"/>
+    <binaryExtension implementation="org.jetbrains.kotlin.idea.util.KotlinJsMetaBinary"/>
   </extensions>
 
 </idea-plugin>