diff --git a/vllm/v1/core/encoder_cache_manager.py b/vllm/v1/core/encoder_cache_manager.py
index d73c05d2cf80..b7837b99be38 100644
--- a/vllm/v1/core/encoder_cache_manager.py
+++ b/vllm/v1/core/encoder_cache_manager.py
@@ -237,7 +237,7 @@ def free(self, request: Request) -> None:
 
         Typically called when a request is finished, cancelled, or aborted.
         """
-        input_ids = self.get_cached_input_ids(request).copy()
+        input_ids = self.get_cached_input_ids(request)
         for input_id in input_ids:
             self.free_encoder_input(request, input_id)