diff --git a/tests/kernels/test_grpo_loss.py b/tests/kernels/test_grpo_loss.py
index c7cbd077..7cc4672a 100644
--- a/tests/kernels/test_grpo_loss.py
+++ b/tests/kernels/test_grpo_loss.py
@@ -94,7 +94,7 @@ def grpo_loss_kernel(kl_type="unbias"):
     T = 32
     H = 256
     V = 1024
-    BLOCK_SIZE_T = 8
+    BLOCK_SIZE_T = 4
     torch.manual_seed(42)
 
     advantages = torch.randn((T,), dtype=torch.float32, device=device_, requires_grad=True)