diff --git a/java/sdk.go b/java/sdk.go
index d972c19..4ef4ee2 100644
--- a/java/sdk.go
+++ b/java/sdk.go
@@ -65,6 +65,12 @@
 		return JAVA_VERSION_9
 	} else if sdk.FinalOrFutureInt() <= 33 {
 		return JAVA_VERSION_11
+	} else if ctx.Config().TargetsJava21() {
+		// Temporary experimental flag to be able to try and build with
+		// java version 21 options.  The flag, if used, just sets Java
+		// 21 as the default version, leaving any components that
+		// target an older version intact.
+		return JAVA_VERSION_21
 	} else {
 		return JAVA_VERSION_17
 	}