diff --git a/tests/test_compile_custom_op.py b/tests/test_compile_custom_op.py
index d6be877e..d4580c38 100644
--- a/tests/test_compile_custom_op.py
+++ b/tests/test_compile_custom_op.py
@@ -136,6 +136,12 @@ def main():
     topk_ids = torch.tensor([[0, 1]] * 4, dtype=torch.int32, device=DEVICE)
     topk_weights = torch.tensor([[0.6, 0.4]] * 4, dtype=torch.float32, device=DEVICE)
 
+    # 1. Warmup: compute activation global scales
+    print("\n[0] Computing activation global scales (warmup)...")
+    runner.compute_activation_global_scales(hidden_states, topk_weights, topk_ids)
+    print(f"  L1 gs: {runner._l1_activation_global_scale:.6f}")
+    print(f"  L2 gs: {runner._l2_activation_global_scale:.6f}")
+
     # 1. Eager mode (baseline)
     print("\n[1/2] Running eager mode (baseline)...")
     runner._ensure_stacked()