diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/BridgesConstruction.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/BridgesConstruction.kt
index f437ac92e83..da729cb6b5c 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/BridgesConstruction.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/lower/BridgesConstruction.kt
@@ -5,8 +5,8 @@
 
 package org.jetbrains.kotlin.ir.backend.js.lower
 
-import org.jetbrains.kotlin.backend.common.ClassLoweringPass
 import org.jetbrains.kotlin.backend.common.CommonBackendContext
+import org.jetbrains.kotlin.backend.common.DeclarationTransformer
 import org.jetbrains.kotlin.backend.common.bridges.FunctionHandle
 import org.jetbrains.kotlin.backend.common.bridges.generateBridges
 import org.jetbrains.kotlin.backend.common.ir.copyTo
@@ -15,6 +15,7 @@ import org.jetbrains.kotlin.backend.common.ir.isMethodOfAny
 import org.jetbrains.kotlin.backend.common.ir.isSuspend
 import org.jetbrains.kotlin.backend.common.lower.*
 import org.jetbrains.kotlin.descriptors.Modality
+import org.jetbrains.kotlin.ir.UNDEFINED_OFFSET
 import org.jetbrains.kotlin.ir.backend.js.JsLoweredDeclarationOrigin
 import org.jetbrains.kotlin.ir.backend.js.ir.JsIrBuilder
 import org.jetbrains.kotlin.ir.backend.js.utils.functionSignature
@@ -23,6 +24,7 @@ import org.jetbrains.kotlin.ir.builders.*
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrValueParameterImpl
 import org.jetbrains.kotlin.ir.expressions.IrExpression
+import org.jetbrains.kotlin.ir.expressions.impl.IrBlockBodyImpl
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.classifierOrNull
 import org.jetbrains.kotlin.ir.util.*
@@ -46,23 +48,20 @@ import org.jetbrains.kotlin.ir.util.*
 //            fun foo(t: Any?) = foo(t as Int)  // Constructed bridge
 //          }
 //
-class BridgesConstruction(val context: CommonBackendContext) : ClassLoweringPass {
+class BridgesConstruction(val context: CommonBackendContext) : DeclarationTransformer {
 
     private val specialBridgeMethods = SpecialBridgeMethods(context)
 
-    override fun lower(irClass: IrClass) {
-        irClass.declarations
-            .asSequence()
-            .filterIsInstance<IrSimpleFunction>()
-            .filter { !it.isStaticMethodOfClass }
-            .toList()
-            .forEach { generateBridges(it, irClass) }
+    override fun transformFlat(declaration: IrDeclaration): List<IrDeclaration>? {
+        if (declaration !is IrSimpleFunction || declaration.isStaticMethodOfClass || declaration.parent !is IrClass) return null
+
+        return generateBridges(declaration)?.let { listOf(declaration) + it }
     }
 
-    private fun generateBridges(function: IrSimpleFunction, irClass: IrClass) {
+    private fun generateBridges(function: IrSimpleFunction): List<IrDeclaration>? {
         // equals(Any?), hashCode(), toString() never need bridges
         if (function.isMethodOfAny())
-            return
+            return null
 
         val (specialOverride: IrSimpleFunction?, specialOverrideInfo) =
             specialBridgeMethods.findSpecialWithOverride(function) ?: Pair(null, null)
@@ -74,6 +73,10 @@ class BridgesConstruction(val context: CommonBackendContext) : ClassLoweringPass
             signature = { FunctionAndSignature(it.function) }
         )
 
+        if (bridgesToGenerate.isEmpty()) return null
+
+        val result = mutableListOf<IrDeclaration>()
+
         for ((from, to) in bridgesToGenerate) {
             if (!from.function.parentAsClass.isInterface &&
                 from.function.isReal &&
@@ -97,8 +100,10 @@ class BridgesConstruction(val context: CommonBackendContext) : ClassLoweringPass
             }
 
 
-            irClass.declarations.add(bridge)
+            result += bridge
         }
+
+        return result
     }
 
     // Ported from from jvm.lower.BridgeLowering
@@ -141,32 +146,32 @@ class BridgesConstruction(val context: CommonBackendContext) : ClassLoweringPass
             overriddenSymbols += bridge.symbol
         }
 
-        context.createIrBuilder(irFunction.symbol).irBlockBody(irFunction) {
-            if (specialMethodInfo != null) {
-                irFunction.valueParameters.take(specialMethodInfo.argumentsToCheck).forEach {
-                    +irIfThen(
-                        context.irBuiltIns.unitType,
-                        irNot(irIs(irGet(it), delegateTo.valueParameters[it.index].type)),
-                        irReturn(specialMethodInfo.defaultValueGenerator(irFunction))
-                    )
+        irFunction.body = IrBlockBodyImpl(UNDEFINED_OFFSET, UNDEFINED_OFFSET) {
+            statements += context.createIrBuilder(irFunction.symbol).irBlockBody(irFunction) {
+                if (specialMethodInfo != null) {
+                    irFunction.valueParameters.take(specialMethodInfo.argumentsToCheck).forEach {
+                        +irIfThen(
+                            context.irBuiltIns.unitType,
+                            irNot(irIs(irGet(it), delegateTo.valueParameters[it.index].type)),
+                            irReturn(specialMethodInfo.defaultValueGenerator(irFunction))
+                        )
+                    }
                 }
-            }
 
-            val call = irCall(delegateTo.symbol)
-            call.dispatchReceiver = irGet(irFunction.dispatchReceiverParameter!!)
-            irFunction.extensionReceiverParameter?.let {
-                call.extensionReceiver = irCastIfNeeded(irGet(it), delegateTo.extensionReceiverParameter!!.type)
-            }
+                val call = irCall(delegateTo.symbol)
+                call.dispatchReceiver = irGet(irFunction.dispatchReceiverParameter!!)
+                irFunction.extensionReceiverParameter?.let {
+                    call.extensionReceiver = irCastIfNeeded(irGet(it), delegateTo.extensionReceiverParameter!!.type)
+                }
 
-            val toTake = irFunction.valueParameters.size - if (call.isSuspend xor irFunction.isSuspend) 1 else 0
+                val toTake = irFunction.valueParameters.size - if (call.isSuspend xor irFunction.isSuspend) 1 else 0
 
-            irFunction.valueParameters.subList(0, toTake).mapIndexed { i, valueParameter ->
-                call.putValueArgument(i, irCastIfNeeded(irGet(valueParameter), delegateTo.valueParameters[i].type))
-            }
+                irFunction.valueParameters.subList(0, toTake).mapIndexed { i, valueParameter ->
+                    call.putValueArgument(i, irCastIfNeeded(irGet(valueParameter), delegateTo.valueParameters[i].type))
+                }
 
-            +irReturn(call)
-        }.apply {
-            irFunction.body = this
+                +irReturn(call)
+            }.statements
         }
 
         return irFunction