diff --git a/tests/unit/test_fmha_v3_stage_c.py b/tests/unit/test_fmha_v3_stage_c.py
index f456d8c0..8dde4630 100644
--- a/tests/unit/test_fmha_v3_stage_c.py
+++ b/tests/unit/test_fmha_v3_stage_c.py
@@ -400,7 +400,8 @@ class FmhaV3StageCMulti:
             final_o_bar.arrive_and_wait()
 
             # === Final O normalization: O *= 1/row_sum ===
-            inv_row_sum = Float32(1.0) / row_sum
+            # DIAG: use 1.0 instead of 1/row_sum to test raw PV output
+            inv_row_sum = Float32(1.0)
 
             tTMrO = cute.make_rmem_tensor(
                 (tTMEM_LOADcO.shape, 128 // corr_tile_size), self.acc_dtype
@@ -447,7 +448,7 @@ class FmhaV3StageCMulti:
 
 def test():
     torch.manual_seed(42)
-    for n in [128, 256]:
+    for n in [128]:
         torch.manual_seed(42)
         m, hd = 128, HEAD_DIM
         q = torch.randn(m, hd, 1, dtype=torch.bfloat16, device='cuda')