diff --git a/.env.sample b/.env.sample
index d4d11d0..73cf4a0 100644
--- a/.env.sample
+++ b/.env.sample
@@ -23,3 +23,4 @@ UPTIME_KUMA_PASSWORD=your-password
 # Ollama for AI-driven auto-update classification
 OLLAMA_BASE_URL=http://192.168.1.20:11434
 OLLAMA_MODEL=gemma4:26b
+OLLAMA_FALLBACK_MODEL=gemma4:12b
diff --git a/update_monitor/classifier.py b/update_monitor/classifier.py
index a27d797..9a072d1 100644
--- a/update_monitor/classifier.py
+++ b/update_monitor/classifier.py
@@ -29,9 +29,11 @@ class Classifier:
         self,
         base_url: str = "",
         model: str = "",
+        fallback_model: str = "",
     ) -> None:
         self.base_url = base_url or os.getenv("OLLAMA_BASE_URL", "http://192.168.1.20:11434")
         self.model = model or os.getenv("OLLAMA_MODEL", "gemma4:26b")
+        self.fallback_model = fallback_model or os.getenv("OLLAMA_FALLBACK_MODEL", "gemma4:12b")
 
     def classify(
         self,
@@ -54,9 +56,23 @@ class Classifier:
         context = context_file.read_text(encoding="utf-8").strip() if context_file.is_file() else None
         messages = self._build_messages(service_dir.name, examples, release_notes, current, latest, context)
 
+        try:
+            return self._classify_with_model(self.model, messages, timeout)
+        except Exception as primary_exc:
+            if not self.fallback_model or self.fallback_model == self.model:
+                return {"action": "manual", "reason": f"Classification error: {primary_exc}"}
+            try:
+                return self._classify_with_model(self.fallback_model, messages, timeout)
+            except Exception as fallback_exc:
+                return {
+                    "action": "manual",
+                    "reason": f"Classification error: {primary_exc}; fallback ({self.fallback_model}) also failed: {fallback_exc}",
+                }
+
+    def _classify_with_model(self, model: str, messages: List[Dict[str, str]], timeout: float) -> Dict[str, str]:
         try:
             payload = json.dumps({
-                "model": self.model,
+                "model": model,
                 "messages": messages,
                 "stream": False,
                 "options": {"temperature": 0},
@@ -79,7 +95,7 @@ class Classifier:
                 raise ValueError(f"Unexpected action value: {action!r}")
             return {"action": action, "reason": result.get("reason", "")}
         except Exception as exc:
-            return {"action": "manual", "reason": f"Classification error: {exc}"}
+            raise RuntimeError(f"model {model}: {exc}") from exc
 
     def _build_messages(
         self,