diff --git a/example/ck_tile/20_grouped_convolution/grouped_convolution_backward_data_invoker.hpp b/example/ck_tile/20_grouped_convolution/grouped_convolution_backward_data_invoker.hpp
index d8a6564f46..f6d20c3d3a 100644
--- a/example/ck_tile/20_grouped_convolution/grouped_convolution_backward_data_invoker.hpp
+++ b/example/ck_tile/20_grouped_convolution/grouped_convolution_backward_data_invoker.hpp
@@ -170,8 +170,15 @@ struct GroupedConvolutionBackwardDataInvoker
                               << ", Vector size C: " << ConvEpilogue::GetVectorSizeC() << std::endl;
                 }
 
-                ave_time = ck_tile::launch_kernel(
-                    s, ck_tile::make_kernel<kBlockPerCu>(Kernel{}, grids, blocks, 0, kargs));
+                auto preprocess = [&]() {
+                    ck_tile::hip_check_error(hipMemsetAsync(
+                        kargs.in_ptr, 0, args.template GetInputByte<InDataType>(), s.stream_id_));
+                };
+
+                ave_time = ck_tile::launch_kernel_time_mask(
+                    s,
+                    preprocess,
+                    ck_tile::make_kernel<kBlockPerCu>(Kernel{}, grids, blocks, 0, kargs));
 
                 return ave_time;
             };
diff --git a/example/ck_tile/20_grouped_convolution/grouped_convolution_backward_weight_invoker.hpp b/example/ck_tile/20_grouped_convolution/grouped_convolution_backward_weight_invoker.hpp
index becc11ff54..0c00bb78e1 100644
--- a/example/ck_tile/20_grouped_convolution/grouped_convolution_backward_weight_invoker.hpp
+++ b/example/ck_tile/20_grouped_convolution/grouped_convolution_backward_weight_invoker.hpp
@@ -171,8 +171,21 @@ struct GroupedConvolutionBackwardWeightInvoker
                           << ", Vector size C: " << ConvEpilogue::GetVectorSizeC() << std::endl;
             }
 
-            ave_time = ck_tile::launch_kernel(
-                s, ck_tile::make_kernel<kBlockPerCu>(Kernel{}, grids, blocks, 0, kargs));
+            auto preprocess = [&]() {
+                if(args.k_batch > 1)
+                {
+                    ck_tile::hip_check_error(
+                        hipMemsetAsync(kargs.wei_ptr,
+                                       0,
+                                       args.template GetWeightByte<WeiDataType>(),
+                                       s.stream_id_));
+                }
+            };
+
+            ave_time = ck_tile::launch_kernel_time_mask(
+                s,
+                preprocess,
+                ck_tile::make_kernel<kBlockPerCu>(Kernel{}, grids, blocks, 0, kargs));
 
             return ave_time;
         };