diff --git a/utils/expand_delta_out_for_conv_f.m b/utils/expand_delta_out_for_conv_f.m
index f841613..78ba3de 100644
--- a/utils/expand_delta_out_for_conv_f.m
+++ b/utils/expand_delta_out_for_conv_f.m
@@ -4,11 +4,11 @@ function expand_delta_out_for_conv_f()
     mem.deltas{current_layer} = bsxfun(@times, mem.deltas{current_layer}, mem.one_over_add_counts);
     last_kernal = config.kernel_size(size(config.kernel_size, 1), :);
     last_layer_size = config.feature_map_sizes{length(config.feature_map_sizes)};
-    expanded_delta = config.NEW_MEM(zeros(last_kernal(1) * last_kernal(2) * config.chs, last_layer_size(1)*last_layer_size(2), config.batch_size));
+    expanded_delta = config.NEW_MEM(zeros(last_kernal(1) * last_kernal(2) * config.output_size(3), last_layer_size(1)*last_layer_size(2), config.batch_size));
     h_step = last_kernal(1) * last_kernal(2);
     for b = 1:config.batch_size
         h_start = 0;
-        for c = 1:config.chs
+        for c = 1:config.output_size(3)
             expanded_delta(h_start+1:h_start+h_step, :, b) = config.IM2COL(mem.deltas{current_layer}(:, :, c, b), ...
                                                                            [last_kernal(1), last_kernal(2)]);
             h_start = h_start + h_step;