diff --git a/build.gradle b/build.gradle
index 97b6ab66..055af7cf 100644
--- a/build.gradle
+++ b/build.gradle
@@ -1,7 +1,7 @@
 // Top-level build file where you can add configuration options common to all sub-projects/modules.
 
 buildscript {
-    ext.kotlin_version = '1.8.22'
+    ext.kotlin_version = '1.9.20'
     repositories {
         google()
         mavenCentral()
@@ -20,6 +20,6 @@ allprojects {
     }
 }
 
-tasks.register('clean') {
-    delete rootProject.buildDir
+tasks.register('clean', Delete) {
+    delete rootProject.layout.buildDirectory
 }