~ Hack: keep protoOf unconditionally
diff --git a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/dce/Dce.kt b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/dce/Dce.kt
index db15f4d..12e2fef 100644
--- a/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/dce/Dce.kt
+++ b/compiler/ir/backend.js/src/org/jetbrains/kotlin/ir/backend/js/dce/Dce.kt
@@ -124,6 +124,7 @@
     addIfNotNull(context.intrinsics.void.owner.backingField)
     addAll(context.testFunsPerFile.values)
     addAll(context.additionalExportedDeclarations)
+    add(context.intrinsics.jsPrototypeOfSymbol.owner)
 }
 
 internal fun RuntimeDiagnostic.unreachableDeclarationMethod(context: JsIrBackendContext) =
@@ -133,4 +134,4 @@
     }
 
 internal fun IrField.isKotlinPackage() =
-    fqNameWhenAvailable?.asString()?.startsWith("kotlin") == true
\ No newline at end of file
+    fqNameWhenAvailable?.asString()?.startsWith("kotlin") == true