diff --git a/python/sglang/srt/layers/attention/flashinfer_backend.py b/python/sglang/srt/layers/attention/flashinfer_backend.py
index de3bbe5cf..af47f2ce2 100644
--- a/python/sglang/srt/layers/attention/flashinfer_backend.py
+++ b/python/sglang/srt/layers/attention/flashinfer_backend.py
@@ -904,6 +904,7 @@ class FlashInferIndicesUpdaterPrefill:
             self.head_dim,
             1,
             q_data_type=self.q_data_type,
+            kv_data_type=self.data_type,
             custom_mask=custom_mask,
             non_blocking=True,
         )