diff --git a/headroom/proxy/handlers/batch.py b/headroom/proxy/handlers/batch.py
index 3681294a4..91c23f640 100644
--- a/headroom/proxy/handlers/batch.py
+++ b/headroom/proxy/handlers/batch.py
@@ -1104,7 +1104,18 @@ class BatchHandlerMixin:
 
             try:
                 request_obj = json.loads(line)
+                # A JSONL line can be valid JSON that isn't a request object
+                # (e.g. a stray array, string, or null). `.get` on it would raise
+                # AttributeError, which the outer `except json.JSONDecodeError`
+                # below does not catch — crashing the whole batch. Pass such lines
+                # through unchanged, like the other non-compressible cases.
+                if not isinstance(request_obj, dict):
+                    compressed_lines.append(line)
+                    total_requests += 1
+                    continue
                 body = request_obj.get("body", {})
+                if not isinstance(body, dict):
+                    body = {}
                 messages = body.get("messages", [])
                 model = body.get("model", "gpt-4")
 
diff --git a/tests/test_proxy_handlers_batch.py b/tests/test_proxy_handlers_batch.py
index 5188b718a..a20a18d1b 100644
--- a/tests/test_proxy_handlers_batch.py
+++ b/tests/test_proxy_handlers_batch.py
@@ -651,6 +651,40 @@ async def test_compress_batch_jsonl_without_optimization_handles_invalid_lines(
     }
 
 
+@pytest.mark.asyncio
+async def test_compress_batch_jsonl_handles_non_object_lines(
+    monkeypatch: pytest.MonkeyPatch,
+) -> None:
+    # A JSONL line that is valid JSON but not a request object (array/string/
+    # null), or a request whose `body` isn't a dict, must pass through instead
+    # of crashing the whole batch (`.get` on a non-dict raises AttributeError,
+    # which the JSONDecodeError guard does not catch).
+    install_batch_support_modules(monkeypatch, tokenizer_count=12)
+    handler = DummyBatchHandler()
+    content = "\n".join(
+        [
+            json.dumps(
+                {"body": {"model": "gpt-4o", "messages": [{"role": "user", "content": "hi"}]}}
+            ),
+            json.dumps([1, 2, 3]),
+            json.dumps("hello"),
+            "null",
+            json.dumps({"body": "not-a-dict"}),
+        ]
+    )
+
+    lines, stats = await handler._compress_batch_jsonl(content, "req-1")
+
+    assert len(lines) == 5
+    assert json.loads(lines[1]) == [1, 2, 3]
+    assert json.loads(lines[2]) == "hello"
+    assert json.loads(lines[3]) is None
+    assert json.loads(lines[4]) == {"body": "not-a-dict"}
+    assert stats["total_requests"] == 5
+    # None of these are JSON decode errors, so the error counter stays at 0.
+    assert stats["errors"] == 0
+
+
 @pytest.mark.asyncio
 async def test_compress_batch_jsonl_uses_pipeline_and_ccr_injection(
     monkeypatch: pytest.MonkeyPatch,