diff --git a/tests/test_llm_analyzer.py b/tests/test_llm_analyzer.py
index c713d7d..9dba071 100644
--- a/tests/test_llm_analyzer.py
+++ b/tests/test_llm_analyzer.py
@@ -133,6 +133,18 @@ def test_empty_narrative_section_is_flagged(analyzer):
     assert "Analysis unavailable" in results["executive_summary"]
 
 
+def test_empty_zeroday_response_records_an_error(analyzer):
+    anomaly = ZeroDayAnomaly(detector="d", title="t", score=90, description="desc")
+    with patch(
+        "urllib.request.urlopen", side_effect=lambda *a, **k: _FakeResponse(_claude_text(""))
+    ):
+        results = analyzer._analyze_zeroday([anomaly])
+
+    assert len(results) == 1
+    assert "raw_analysis" not in results[0]
+    assert "empty response" in results[0]["error"]
+
+
 def test_analyze_single_finding_propagates_failure(analyzer):
     with patch("urllib.request.urlopen", side_effect=_http_error(401)):
         with pytest.raises(LLMError):