diff --git a/apps/api/src/services/ai_router.py b/apps/api/src/services/ai_router.py
index e0e8cd69..fd6c69f8 100644
--- a/apps/api/src/services/ai_router.py
+++ b/apps/api/src/services/ai_router.py
@@ -163,7 +163,7 @@ class RoutingDecision:
         # 向後相容
         self.model = self.selected_model
         self.reason = self.routing_reason
-        self.fallback_models = [model for _, model in self.fallback_chain]
+        self.fallback_models = [model for _, model in self.fallback_chain if model != self.selected_model]
 
     def to_dict(self) -> dict:
         """轉換為字典 (API 回應用)"""