diff --git a/examples/cnn_mnist_dag.m b/examples/cnn_mnist_dag.m
index c80790a7..92b08cc2 100644
--- a/examples/cnn_mnist_dag.m
+++ b/examples/cnn_mnist_dag.m
@@ -53,7 +53,7 @@
 % --------------------------------------------------------------------
 images = imdb.images.data(:,:,:,batch) ;
 labels = imdb.images.labels(1,batch) ;
-if numel(opts.useGpu) > 0
+if opts.useGpu > 0
   images = gpuArray(images) ;
 end
 inputs = {'input', images, 'label', labels} ;