diff --git a/python/qrcodegen-batch-test.py b/python/qrcodegen-batch-test.py
index 5e6d729..3acf236 100644
--- a/python/qrcodegen-batch-test.py
+++ b/python/qrcodegen-batch-test.py
@@ -32,7 +32,7 @@ if sys.version_info.major < 3:
 CHILD_PROGRAMS = [
 	["python2", "../python/qrcodegen-worker.py"],  # Python 2 program
 	["python3", "../python/qrcodegen-worker.py"],  # Python 3 program
-	["java", "-cp", "../java", "io/nayuki/qrcodegen/QrCodeGeneratorWorker"],  # Java program
+	["java", "-cp", "../java", "-ea:io.nayuki.qrcodegen...", "io/nayuki/qrcodegen/QrCodeGeneratorWorker"],  # Java program
 	["../c/qrcodegen-worker"],  # C program
 	["../cpp/QrCodeGeneratorWorker"],  # C++ program
 	["../rust/target/debug/examples/qrcodegen-worker"],  # Rust program