diff --git a/dsv4/kernels/router/nvfp4_fused_router_kernel.py b/dsv4/kernels/router/nvfp4_fused_router_kernel.py
index 308c1b11..9f88dbec 100644
--- a/dsv4/kernels/router/nvfp4_fused_router_kernel.py
+++ b/dsv4/kernels/router/nvfp4_fused_router_kernel.py
@@ -69,19 +69,12 @@ class Nvfp4FusedRouterKernel:
         self.cta_group = tcgen05.CtaGroup.TWO if self.use_2cta_instrs else tcgen05.CtaGroup.ONE
         self.arch = "sm_100"
 
-        # Set up MMA instruction shapes before any MMA creation calls
-        # ALL shape values must be cutlass.Int32 so CuTe layout construction
-        # produces static (not dynamic) dimensions. Python ints cause
-        # "Expected an MLIR object (got None)" in _pack_shape.
-        self.mma_inst_shape_mn = (
-            cutlass.Int32(mma_tiler_mnk[0]),
-            cutlass.Int32(mma_tiler_mnk[1]),
-        )
-        # round_up with Python math, then wrap in cutlass.Int32
-        sfb_n = ((mma_tiler_mnk[1] + 128 - 1) // 128) * 128
+        # Set up MMA instruction shapes
+        # These are now used inside @cute.jit context, so cute.round_up is fine
+        self.mma_inst_shape_mn = (mma_tiler_mnk[0], mma_tiler_mnk[1])
         self.mma_inst_shape_mn_sfb = (
-            cutlass.Int32(mma_tiler_mnk[0] // (2 if self.use_2cta_instrs else 1)),
-            cutlass.Int32(sfb_n),
+            self.mma_inst_shape_mn[0] // (2 if self.use_2cta_instrs else 1),
+            cute.round_up(self.mma_inst_shape_mn[1], 128),
         )
 
         # 6-warp specialization (no scheduler warp for dense GEMM)
@@ -132,12 +125,12 @@ class Nvfp4FusedRouterKernel:
         self.mma_tiler = (
             self.mma_inst_shape_mn[0],
             self.mma_inst_shape_mn[1],
-            cutlass.Int32(self.mma_tiler_mnk[2]),
+            self.mma_tiler_mnk[2],
         )
         self.mma_tiler_sfb = (
             self.mma_inst_shape_mn_sfb[0],
             self.mma_inst_shape_mn_sfb[1],
-            cutlass.Int32(self.mma_tiler_mnk[2]),
+            self.mma_tiler_mnk[2],
         )
         self.cta_tile_shape_mnk = (
             self.mma_tiler[0] // cute.size(tiled_mma.thr_id.shape),
@@ -151,18 +144,10 @@ class Nvfp4FusedRouterKernel:
         )
 
         self.cluster_layout_vmnk = cute.tiled_divide(
-            cute.make_layout((
-                cutlass.Int32(self.cluster_shape_mn[0]),
-                cutlass.Int32(self.cluster_shape_mn[1]),
-                cutlass.Int32(1),
-            )),
+            cute.make_layout((*self.cluster_shape_mn, 1)),
             (tiled_mma.thr_id.shape,))
         self.cluster_layout_sfb_vmnk = cute.tiled_divide(
-            cute.make_layout((
-                cutlass.Int32(self.cluster_shape_mn[0]),
-                cutlass.Int32(self.cluster_shape_mn[1]),
-                cutlass.Int32(1),
-            )),
+            cute.make_layout((*self.cluster_shape_mn, 1)),
             (tiled_mma_sfb.thr_id.shape,))
 
         self.num_mcast_ctas_a = cute.size(self.cluster_layout_vmnk.shape[2])