diff --git a/flash_attn/cute/flash_bwd_sm90.py b/flash_attn/cute/flash_bwd_sm90.py
index 641adef4846..deb40f7939d 100644
--- a/flash_attn/cute/flash_bwd_sm90.py
+++ b/flash_attn/cute/flash_bwd_sm90.py
@@ -295,7 +295,14 @@ def __call__(
         softcap: Float32 | float | None = None,
         window_size_left: Int32 | int | None = None,
         window_size_right: Int32 | int | None = None,
+        mdQ_semaphore: Optional[cute.Tensor] = None,
+        mdK_semaphore: Optional[cute.Tensor] = None,
+        mdV_semaphore: Optional[cute.Tensor] = None,
     ):
+        assert mdQ_semaphore is None and mdK_semaphore is None and mdV_semaphore is None, (
+            "determinism not supported yet for Sm90"
+        )
+
         self._check_type(
             *(
                 t.element_type if t is not None else None