diff --git a/services/hermes/plugins/auto-router/__init__.py b/services/hermes/plugins/auto-router/__init__.py
index e45066b71..c6b36bdda 100644
--- a/services/hermes/plugins/auto-router/__init__.py
+++ b/services/hermes/plugins/auto-router/__init__.py
@@ -438,7 +438,9 @@ def _jetson_route(text: str, timeout: float) -> tuple[tuple[str, str, str] | Non
             "required": ["provider", "effort", "priority"],
             "additionalProperties": False,
         },
-        "keep_alive": "-1",
+        # Ollama accepts a numeric negative duration as "keep loaded". A
+        # string without a unit is rejected by current releases with HTTP 400.
+        "keep_alive": -1,
         "options": {"temperature": 0, "num_ctx": 2048, "num_predict": 48},
         "messages": [
             {"role": "system", "content": system_prompt},
@@ -927,7 +929,7 @@ def _rewarm_classifier() -> None:
             "model": JETSON_MODEL,
             "prompt": "Reply with P",
             "stream": False,
-            "keep_alive": "-1",
+            "keep_alive": -1,
             "options": {"temperature": 0, "num_ctx": 128, "num_predict": 1},
         }
         request = urllib.request.Request(
diff --git a/testing/tests/test_hermes_auto_router.py b/testing/tests/test_hermes_auto_router.py
index be4d55514..95a89c222 100644
--- a/testing/tests/test_hermes_auto_router.py
+++ b/testing/tests/test_hermes_auto_router.py
@@ -3,6 +3,8 @@
 from __future__ import annotations
 
 import importlib.util
+import io
+import json
 import sys
 from pathlib import Path
 
@@ -172,6 +174,32 @@ def test_jetson_requests_one_structured_provider_effort_priority_vote(monkeypatc
     assert calls == [("Review the architecture", 2.5)]
 
 
+def test_ollama_requests_use_numeric_keep_alive(monkeypatch):
+    payloads = []
+
+    def urlopen(request, timeout):
+        payloads.append(json.loads(request.data))
+        if request.full_url.endswith("/chat"):
+            body = {
+                "message": {
+                    "content": '{"provider":"C","effort":"L","priority":"F"}'
+                }
+            }
+        else:
+            body = {"response": "P"}
+        return io.BytesIO(json.dumps(body).encode())
+
+    monkeypatch.setattr(router.urllib.request, "urlopen", urlopen)
+
+    vote, _ = router._jetson_route("Answer quickly", 2.5)
+    assert vote == ("C", "L", "F")
+    assert payloads[0]["keep_alive"] == -1
+
+    router._classifier_warm_lock.acquire()
+    router._rewarm_classifier()
+    assert payloads[1]["keep_alive"] == -1
+
+
 def test_every_auto_classification_consults_jetson_and_keeps_safety_floors(monkeypatch):
     calls = []