diff --git a/codegen-test/build.gradle.kts b/codegen-test/build.gradle.kts
index 3c4abb4..38970d3 100644
--- a/codegen-test/build.gradle.kts
+++ b/codegen-test/build.gradle.kts
@@ -20,7 +20,7 @@ buildscript {
 
 plugins {
     id("java")
-    id("org.jetbrains.kotlin.jvm") version "2.1.20"
+    id("org.jetbrains.kotlin.jvm") version "2.1.21"
     id("org.domaframework.doma.compile") version "4.0.0"
     id("org.domaframework.doma.codegen")
 }