diff --git a/flashinfer/prefill.py b/flashinfer/prefill.py
index 618f6fbbf6..1cfc900091 100755
--- a/flashinfer/prefill.py
+++ b/flashinfer/prefill.py
@@ -3821,8 +3821,8 @@ def fmha_v2_prefill_deepseek(
         If return_lse is True, the output will be a tuple of two tensors, the first is the output tensor, the second is the lse tensor.
         If return_lse is False, the output will be a single tensor.
     """
-    if not is_sm120a_supported(query.device):
-        raise ValueError("fmha_v2_prefill_deepseek is only supported on SM120 GPUs.")
+    if not (is_sm120a_supported(query.device) or is_sm121a_supported(query.device)):
+        raise ValueError("fmha_v2_prefill_deepseek is only supported on SM12x GPUs.")
     assert query.shape[3] == 192 and key.shape[3] == 192 and value.shape[3] == 128, (
         "currently only support deepseek r1 192 query and 128 value"
     )
diff --git a/tests/attention/test_fmha_v2_prefill_deepseek.py b/tests/attention/test_fmha_v2_prefill_deepseek.py
index 2dad1355ce..8c538a98cf 100755
--- a/tests/attention/test_fmha_v2_prefill_deepseek.py
+++ b/tests/attention/test_fmha_v2_prefill_deepseek.py
@@ -5,7 +5,7 @@
 
 from flashinfer.prefill import fmha_v2_prefill_deepseek
 from tests.utils_fp8 import to_float8
-from flashinfer.utils import is_sm120a_supported
+from flashinfer.utils import is_sm120a_supported, is_sm121a_supported
 
 
 def attention_ref(
@@ -57,8 +57,11 @@ def attention_ref(
 def test_fmha_v2_prefill_deepseek(
     batch_size, num_heads, head_dim_qk, head_dim_v, seq_len, qkv_dtype, o_dtype
 ):
-    if not is_sm120a_supported(torch.device("cuda")):
-        pytest.skip("fmha_v2_prefill_deepseek is only supported on SM120 GPUs.")
+    if not (
+        is_sm120a_supported(torch.device("cuda"))
+        or is_sm121a_supported(torch.device("cuda"))
+    ):
+        pytest.skip("fmha_v2_prefill_deepseek is only supported on SM12x GPUs.")
     torch.manual_seed(42)
 
     def initialize_tensors(batch_size, num_heads, head_dim_qk, head_dim_v, seq_len):