diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt
index 3db13aaf700..66e8def9c05 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/compiler.kt
@@ -6,8 +6,8 @@
 package org.jetbrains.kotlin.ir.backend.js
 
 import com.intellij.openapi.project.Project
+import org.jetbrains.kotlin.backend.common.*
 import org.jetbrains.kotlin.backend.common.lower.*
-import org.jetbrains.kotlin.backend.common.runOnFilePostfix
 import org.jetbrains.kotlin.config.CompilerConfiguration
 import org.jetbrains.kotlin.config.languageVersionSettings
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
@@ -57,7 +57,7 @@ fun compile(
 
     context.performInlining(moduleFragment)
 
-    moduleFragment.files.forEach { context.lower(it) }
+    context.lower(moduleFragment.files)
     val transformer = SecondaryCtorLowering.CallsiteRedirectionTransformer(context)
     moduleFragment.files.forEach { it.accept(transformer, null) }
 
@@ -84,28 +84,34 @@ private fun JsIrBackendContext.performInlining(moduleFragment: IrModuleFragment)
     }
 }
 
-private fun JsIrBackendContext.lower(file: IrFile) {
-    LateinitLowering(this, true).lower(file)
-    DefaultArgumentStubGenerator(this).runOnFilePostfix(file)
-    DefaultParameterInjector(this).runOnFilePostfix(file)
-    SharedVariablesLowering(this).runOnFilePostfix(file)
-    EnumClassLowering(this).runOnFilePostfix(file)
-    EnumUsageLowering(this).lower(file)
-    ReturnableBlockLowering(this).lower(file)
-    LocalDeclarationsLowering(this).runOnFilePostfix(file)
-    InnerClassesLowering(this).runOnFilePostfix(file)
-    InnerClassConstructorCallsLowering(this).runOnFilePostfix(file)
-    PropertiesLowering().lower(file)
-    InitializersLowering(this, JsLoweredDeclarationOrigin.CLASS_STATIC_INITIALIZER, false).runOnFilePostfix(file)
-    MultipleCatchesLowering(this).lower(file)
-    BridgesConstruction(this).runOnFilePostfix(file)
-    TypeOperatorLowering(this).lower(file)
-    BlockDecomposerLowering(this).runOnFilePostfix(file)
-    SecondaryCtorLowering(this).runOnFilePostfix(file)
-    CallableReferenceLowering(this).lower(file)
-    IntrinsicifyCallsLowering(this).lower(file)
+private fun JsIrBackendContext.lower(files: List<IrFile>) {
+    LateinitLowering(this, true).lower(files)
+    DefaultArgumentStubGenerator(this).runOnFilePostfix(files)
+    DefaultParameterInjector(this).runOnFilePostfix(files)
+    SharedVariablesLowering(this).runOnFilePostfix(files)
+    EnumClassLowering(this).runOnFilePostfix(files)
+    EnumUsageLowering(this).lower(files)
+    ReturnableBlockLowering(this).lower(files)
+    LocalDeclarationsLowering(this).runOnFilePostfix(files)
+    InnerClassesLowering(this).runOnFilePostfix(files)
+    InnerClassConstructorCallsLowering(this).runOnFilePostfix(files)
+    PropertiesLowering().lower(files)
+    InitializersLowering(this, JsLoweredDeclarationOrigin.CLASS_STATIC_INITIALIZER, false).runOnFilePostfix(files)
+    MultipleCatchesLowering(this).lower(files)
+    BridgesConstruction(this).runOnFilePostfix(files)
+    TypeOperatorLowering(this).lower(files)
+    BlockDecomposerLowering(this).runOnFilePostfix(files)
+    SecondaryCtorLowering(this).runOnFilePostfix(files)
+    CallableReferenceLowering(this).lower(files)
+    IntrinsicifyCallsLowering(this).lower(files)
 }
 
+private fun FileLoweringPass.lower(files: List<IrFile>) = files.forEach { lower(it) }
+private fun DeclarationContainerLoweringPass.runOnFilePostfix(files: List<IrFile>) = files.forEach { runOnFilePostfix(it) }
+private fun BodyLoweringPass.runOnFilePostfix(files: List<IrFile>) = files.forEach { runOnFilePostfix(it) }
+private fun FunctionLoweringPass.runOnFilePostfix(files: List<IrFile>) = files.forEach { runOnFilePostfix(it) }
+private fun ClassLoweringPass.runOnFilePostfix(files: List<IrFile>) = files.forEach { runOnFilePostfix(it) }
+
 // TODO find out why duplicates occur
 private fun IrModuleFragment.removeDuplicates(): IrModuleFragment {