diff --git a/tests/integration/test_parser_external_predict.py b/tests/integration/test_parser_external_predict.py
new file mode 100644
index 00000000..5cd71c6a
--- /dev/null
+++ b/tests/integration/test_parser_external_predict.py
@@ -0,0 +1,17 @@
+from __future__ import annotations
+
+from openamp_foundry.cli.main import build_parser
+
+
+def test_external_predict_parser_defaults_are_stable():
+    parser = build_parser()
+    args = parser.parse_args([
+        "external-predict",
+        "--pilot-csv",
+        "panel.csv",
+    ])
+
+    assert args.command == "external-predict"
+    assert args.pilot_csv == "panel.csv"
+    assert args.out_fasta == "outputs/pilot_panel.fasta"
+    assert args.out_checklist == "outputs/external_predict_checklist.md"