diff --git a/vllm/platforms/rocm.py b/vllm/platforms/rocm.py
index 0af98d562c12..329445d3757e 100644
--- a/vllm/platforms/rocm.py
+++ b/vllm/platforms/rocm.py
@@ -438,8 +438,6 @@ def get_attn_backend_cls(
         device_capability = cls.get_device_capability()
         assert device_capability is not None
 
-        attn_selector_config = attn_selector_config._replace(block_size=None)
-
         # First try checking just the selected backend, if there is one.
         if selected_backend is not None:
             try: