diff --git a/vllm/platforms/rocm.py b/vllm/platforms/rocm.py
index f1fd333180..76be83c063 100644
--- a/vllm/platforms/rocm.py
+++ b/vllm/platforms/rocm.py
@@ -438,6 +438,8 @@ class RocmPlatform(Platform):
         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: