diff --git a/build.gradle b/build.gradle
index 8f1b9af..ccb6c44 100644
--- a/build.gradle
+++ b/build.gradle
@@ -8,8 +8,10 @@ ext {
 }
 
 subprojects {
+  java {
     sourceCompatibility = '21'
     targetCompatibility = '21'
+  }
 }
 
 if (JavaVersion.current().isJava8Compatible()) {