diff --git a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDeclarationTable.kt b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDeclarationTable.kt
index 69a488afe4b..e96342f716c 100644
--- a/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDeclarationTable.kt
+++ b/compiler/ir/serialization.js/src/org/jetbrains/kotlin/ir/backend/js/lower/serialization/ir/JsDeclarationTable.kt
@@ -8,8 +8,8 @@ package org.jetbrains.kotlin.ir.backend.js.lower.serialization.ir
 import org.jetbrains.kotlin.backend.common.serialization.GlobalDeclarationTable
 import org.jetbrains.kotlin.backend.common.serialization.IdSignatureClashTracker
 import org.jetbrains.kotlin.backend.common.serialization.signature.IdSignatureSerializer
-import org.jetbrains.kotlin.descriptors.PropertyDescriptor
 import org.jetbrains.kotlin.ir.declarations.IrDeclaration
+import org.jetbrains.kotlin.ir.declarations.IrProperty
 import org.jetbrains.kotlin.ir.declarations.IrSimpleFunction
 import org.jetbrains.kotlin.ir.declarations.IrTypeParameter
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
@@ -24,19 +24,15 @@ class JsUniqIdClashTracker : IdSignatureClashTracker {
 
         if (signature in committedIdSignatures) {
             val clashedDeclaration = committedIdSignatures[signature]!!
-            if (declaration !is IrTypeParameter &&
-                (declaration.parent !is IrSimpleFunction || declaration.parent === clashedDeclaration.parent)
-            ) {
+            val parent = declaration.parent
+            val clashedParent = clashedDeclaration.parent
+            if (declaration is IrTypeParameter && parent is IrSimpleFunction && parent.parent is IrProperty && parent !== clashedParent) {
+                // Check whether they are type parameters of the same extension property but different accessors
+                require(clashedParent is IrSimpleFunction)
+                require(clashedParent.correspondingPropertySymbol === parent.correspondingPropertySymbol)
+            } else {
                 // TODO: handle clashes properly
                 error("IdSignature clash: $signature; Existed declaration ${clashedDeclaration.render()} clashed with new ${declaration.render()}")
-            } else {
-                // Check whether they are type parameters of the same extension property but different accessors
-                val parent = declaration.parent
-                val clashedParent = clashedDeclaration.parent
-                require(parent is IrSimpleFunction)
-                require(clashedParent is IrSimpleFunction)
-                require(clashedDeclaration !== parent)
-                require(clashedParent.correspondingPropertySymbol === parent.correspondingPropertySymbol)
             }
         }