diff --git a/vllm/v1/attention/backends/mla/rocm_aiter_mla.py b/vllm/v1/attention/backends/mla/rocm_aiter_mla.py
index e8921f8a1c403..751726c15880d 100644
--- a/vllm/v1/attention/backends/mla/rocm_aiter_mla.py
+++ b/vllm/v1/attention/backends/mla/rocm_aiter_mla.py
@@ -122,7 +122,11 @@ class AiterMLAMetadataBuilder(MLACommonMetadataBuilder[AiterMLAMetadata]):
         ).unsqueeze(0) < seq_lens_device.unsqueeze(1)
         paged_kv_indices = block_table_tensor[mask]
 
-        paged_kv_last_page_len = torch.where(seq_lens_device == 0, 1, seq_lens_device)
+        # kernel block size is always 1, so each page has exactly 1 token.
+        # last_page_len should always be 1 regardless of sequence length.
+        paged_kv_last_page_len = torch.ones(
+            num_reqs, dtype=seq_lens_device.dtype, device=device
+        )
 
         paged_kv_indptr = torch.cat(
             [