diff --git a/Quelea/build.gradle b/Quelea/build.gradle
index 09028246f..58714f0c8 100644
--- a/Quelea/build.gradle
+++ b/Quelea/build.gradle
@@ -70,6 +70,11 @@ task removeDist(type: Delete) {
     delete "bundlejre"
 }
 
+compileJava   {
+    sourceCompatibility = '21'
+    targetCompatibility = '21'
+}
+
 clean.finalizedBy(removeDist)
 compileJava.finalizedBy(dependencyUpdates)