diff --git a/src/nvfp4_megamoe_kernel/nvfp4_mega_moe.py b/src/nvfp4_megamoe_kernel/nvfp4_mega_moe.py
index a6c8b9a8..95ff2bda 100644
--- a/src/nvfp4_megamoe_kernel/nvfp4_mega_moe.py
+++ b/src/nvfp4_megamoe_kernel/nvfp4_mega_moe.py
@@ -360,4 +360,8 @@ def nvfp4_mega_moe_full(
 
     # Step 6: Final scatter — routing weights applied ONCE
     y.zero_()
-    y.index_add_(0, slot_token, slot_weight[:, None] * l2_slots)
+    y.index_add_(
+        0,
+        slot_token,
+        l2_slots * slot_weight.to(l2_slots.dtype).unsqueeze(1),
+    )