diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsLoweringPhases.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsLoweringPhases.kt
index eb23c81bae4..113211a6120 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsLoweringPhases.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/JsLoweringPhases.kt
@@ -514,6 +514,19 @@ private val multipleCatchesLoweringPhase = makeBodyLoweringPhase(
     description = "Replace multiple catches with single one"
 )
 
+private val errorExpressionLoweringPhase = makeBodyLoweringPhase(
+    ::JsErrorExpressionLowering,
+    name = "errorExpressionLoweringPhase",
+    description = "Transform error expressions into simple ir code",
+    prerequisite = setOf(multipleCatchesLoweringPhase)
+)
+
+private val errorDeclarationLoweringPhase = makeDeclarationTransformerPhase(
+    ::JsErrorDeclarationLowering,
+    name = "errorDeclarationLoweringPhase",
+    description = "Transform error declarations into simple ir code"
+)
+
 private val bridgesConstructionPhase = makeDeclarationTransformerPhase(
     ::BridgesConstruction,
     name = "BridgesConstruction",
@@ -534,7 +547,7 @@ private val typeOperatorLoweringPhase = makeBodyLoweringPhase(
     prerequisite = setOf(
         bridgesConstructionPhase,
         removeInlineFunctionsWithReifiedTypeParametersLoweringPhase,
-        singleAbstractMethodPhase
+        singleAbstractMethodPhase, errorExpressionLoweringPhase
     )
 )
 
@@ -707,6 +720,8 @@ val loweringList = listOf<Lowering>(
     es6ConstructorLowering,
     varargLoweringPhase,
     multipleCatchesLoweringPhase,
+    errorExpressionLoweringPhase,
+    errorDeclarationLoweringPhase,
     bridgesConstructionPhase,
     typeOperatorLoweringPhase,
     secondaryConstructorLoweringPhase,