diff --git a/vllm/distributed/kv_transfer/kv_connector/v1/nixl/worker.py b/vllm/distributed/kv_transfer/kv_connector/v1/nixl/worker.py
index ea8b46c28f9c..1b561eb81e4b 100644
--- a/vllm/distributed/kv_transfer/kv_connector/v1/nixl/worker.py
+++ b/vllm/distributed/kv_transfer/kv_connector/v1/nixl/worker.py
@@ -464,11 +464,14 @@ def _sync_block_size_with_kernel(self) -> None:
                 kernel_block_size,
             )
             assert self.block_size > kernel_block_size
-            self._physical_blocks_per_logical_kv_block = (
-                self.block_size // kernel_block_size
-            )
-            self.block_size = kernel_block_size
-            self.num_blocks *= self._physical_blocks_per_logical_kv_block
+            if self.vllm_config.use_v2_model_runner:
+                self._physical_blocks_per_logical_kv_block = 1
+            else:
+                self._physical_blocks_per_logical_kv_block = (
+                    self.block_size // kernel_block_size
+                )
+                self.block_size = kernel_block_size
+                self.num_blocks *= self._physical_blocks_per_logical_kv_block
 
     def _nixl_handshake(
         self,