Move up to match Lucene source compatibility
diff --git a/nouveau/build.gradle b/nouveau/build.gradle
index fd15952..23db6f7 100644
--- a/nouveau/build.gradle
+++ b/nouveau/build.gradle
@@ -46,7 +46,7 @@
 version = '1.0-SNAPSHOT'
 
 java {
-    sourceCompatibility = "11"
+    sourceCompatibility = "21"
 }
 
 jar {