diff --git a/tools/test-js-with-puppeteer b/tools/test-js-with-puppeteer
index 17e4ac153b..b6c5f177e4 100755
--- a/tools/test-js-with-puppeteer
+++ b/tools/test-js-with-puppeteer
@@ -61,7 +61,7 @@ def run_tests(files: Iterable[str], external_host: str) -> None:
         current_test_num = test_number
         for test_file in test_files[test_number:]:
             test_name = os.path.basename(test_file)
-            cmd = ["node", test_file]
+            cmd = ["node", "--unhandled-rejections=strict", test_file]
             print(
                 "\n\n===================== {}\nRunning {}\n\n".format(
                     test_name, " ".join(map(shlex.quote, cmd))