diff --git a/wizard-work/spark/verify_result.py b/wizard-work/spark/verify_result.py
index 7962798..108832b 100644
--- a/wizard-work/spark/verify_result.py
+++ b/wizard-work/spark/verify_result.py
@@ -1,7 +1,14 @@
 #!/usr/bin/env python3
 import json
+
+
+def _check(cond, msg="check failed"):
+    """Explicit failure path -- survives `python3 -O`, where `assert` is compiled away."""
+    if not cond:
+        raise SystemExit(f"FAIL: {msg}")
+
 with open("/root/.hermes/wizard-outputs/spark/scrape_result.json") as f:
     data = json.load(f)
-assert data["title"] == "Example Domain", f"wrong title: {data['title']}"
-assert data["status"] == "success", f"wrong status: {data['status']}"
+_check(data["title"] == "Example Domain", f"wrong title: {data['title']}")
+_check(data["status"] == "success", f"wrong status: {data['status']}")
 print("VALID")
\ No newline at end of file