diff --git a/compiler/cli/src/org/jetbrains/kotlin/cli/metadata/K2MetadataKlibSerializer.kt b/compiler/cli/src/org/jetbrains/kotlin/cli/metadata/K2MetadataKlibSerializer.kt
index dca69532cb1..5c3659df68e 100644
--- a/compiler/cli/src/org/jetbrains/kotlin/cli/metadata/K2MetadataKlibSerializer.kt
+++ b/compiler/cli/src/org/jetbrains/kotlin/cli/metadata/K2MetadataKlibSerializer.kt
@@ -91,6 +91,7 @@ internal class K2MetadataKlibSerializer(private val metadataVersion: BuiltInsBin
             destDir.absolutePath,
             configuration[CommonConfigurationKeys.MODULE_NAME]!!,
             nopack = true,
+            perFile = false,
             manifestProperties = null,
             dataFlowGraph = null,
             builtInsPlatform = BuiltInsPlatform.COMMON
diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
index b2fa0638e49..6a3cec379fa 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/klib.kt
@@ -179,7 +179,8 @@ fun generateKLib(
         moduleFragment,
         expectDescriptorToSymbol,
         icData,
-        nopack
+        nopack,
+        false
     )
 }
 
@@ -447,7 +448,8 @@ fun serializeModuleIntoKlib(
     moduleFragment: IrModuleFragment,
     expectDescriptorToSymbol: MutableMap<DeclarationDescriptor, IrSymbol>,
     cleanFiles: List<KotlinFileSerializedData>,
-    nopack: Boolean
+    nopack: Boolean,
+    perFile: Boolean
 ) {
     assert(files.size == moduleFragment.files.size)
 
@@ -525,6 +527,7 @@ fun serializeModuleIntoKlib(
         manifestProperties = null,
         moduleName = moduleName,
         nopack = nopack,
+        perFile = perFile,
         output = klibPath,
         versions = versions,
         builtInsPlatform = BuiltInsPlatform.JS
diff --git a/compiler/util-klib/src/org/jetbrains/kotlin/library/impl/KotlinLibraryImpl.kt b/compiler/util-klib/src/org/jetbrains/kotlin/library/impl/KotlinLibraryImpl.kt
index c9f2c898b7d..cb1f37e905e 100644
--- a/compiler/util-klib/src/org/jetbrains/kotlin/library/impl/KotlinLibraryImpl.kt
+++ b/compiler/util-klib/src/org/jetbrains/kotlin/library/impl/KotlinLibraryImpl.kt
@@ -234,7 +234,8 @@ open class KotlinLibraryImpl(
 fun createKotlinLibrary(
     libraryFile: File,
     component: String,
-    isDefault: Boolean = false
+    isDefault: Boolean = false,
+    perFile: Boolean = false
 ): KotlinLibrary {
     val baseAccess = BaseLibraryAccess<KotlinLibraryLayout>(libraryFile, component)
     val metadataAccess = MetadataLibraryAccess<MetadataKotlinLibraryLayout>(libraryFile, component)
@@ -242,8 +243,7 @@ fun createKotlinLibrary(
 
     val base = BaseKotlinLibraryImpl(baseAccess, isDefault)
     val metadata = MetadataLibraryImpl(metadataAccess)
-    val ir = IrMonoliticLibraryImpl(irAccess)
-//    val ir = IrPerFileLibraryImpl(irAccess)
+    val ir = if (perFile) IrPerFileLibraryImpl(irAccess) else IrMonoliticLibraryImpl(irAccess)
 
     return KotlinLibraryImpl(base, metadata, ir)
 }
diff --git a/compiler/util-klib/src/org/jetbrains/kotlin/library/impl/KotlinLibraryWriterImpl.kt b/compiler/util-klib/src/org/jetbrains/kotlin/library/impl/KotlinLibraryWriterImpl.kt
index f31638a7d1b..5ac0ac5b8f9 100644
--- a/compiler/util-klib/src/org/jetbrains/kotlin/library/impl/KotlinLibraryWriterImpl.kt
+++ b/compiler/util-klib/src/org/jetbrains/kotlin/library/impl/KotlinLibraryWriterImpl.kt
@@ -111,13 +111,26 @@ fun buildKotlinLibrary(
     output: String,
     moduleName: String,
     nopack: Boolean,
+    perFile: Boolean,
     manifestProperties: Properties?,
     dataFlowGraph: ByteArray?,
     builtInsPlatform: BuiltInsPlatform,
     nativeTargets: List<String> = emptyList()
 ): KotlinLibraryLayout {
 
-    val library = KotlinLibraryWriterImpl(File(output), moduleName, versions, builtInsPlatform, nativeTargets, nopack)
+    val klibDirectory = File(output)
+    val layout = KotlinLibraryLayoutForWriter(klibDirectory)
+    val irWriter = if (perFile) IrPerFileWriterImpl(layout) else IrMonoliticWriterImpl(layout)
+    val library = KotlinLibraryWriterImpl(
+        klibDirectory,
+        moduleName,
+        versions,
+        builtInsPlatform,
+        nativeTargets,
+        nopack,
+        layout = layout,
+        ir = irWriter
+    )
 
     library.addMetadata(metadata)
 
@@ -133,10 +146,37 @@ fun buildKotlinLibrary(
     return library.layout
 }
 
+class KotlinLibraryOnlyIrWriter(output: String, moduleName: String, versions: KotlinLibraryVersioning, platform: BuiltInsPlatform, nativeTargets: List<String>, perFile: Boolean) {
+    val outputDir = File(output)
+    val library = createLibrary(perFile, moduleName, versions, platform, nativeTargets, outputDir)
+
+    private fun createLibrary(
+        perFile: Boolean,
+        moduleName: String,
+        versions: KotlinLibraryVersioning,
+        platform: BuiltInsPlatform,
+        nativeTargets: List<String>,
+        directory: File
+    ): KotlinLibraryWriterImpl {
+        val layout = KotlinLibraryLayoutForWriter(directory)
+        val irWriter = if (perFile) IrPerFileWriterImpl(layout) else IrMonoliticWriterImpl(layout)
+        return KotlinLibraryWriterImpl(directory, moduleName, versions, platform, nativeTargets, nopack = true, layout = layout, ir = irWriter)
+    }
+
+    fun invalidate() {
+        outputDir.deleteRecursively()
+        library.layout.irDir.mkdirs()
+    }
+
+    fun writeIr(serializedIrModule: SerializedIrModule) {
+        library.addIr(serializedIrModule)
+    }
+}
+
 enum class BuiltInsPlatform {
     JVM, JS, NATIVE, COMMON;
 
     companion object {
         fun parseFromString(name: String): BuiltInsPlatform? = values().firstOrNull { it.name == name }
     }
-}
+}
\ No newline at end of file