diff --git a/Magick++/demo/demo.cpp b/Magick++/demo/demo.cpp
index e9cb4b1..59b1a5b 100644
--- a/Magick++/demo/demo.cpp
+++ b/Magick++/demo/demo.cpp
@@ -503,7 +503,7 @@
for_each( montage.begin(), montage.end(), compressTypeImage( RLECompression) );
cout << "Writing image \"demo_out.miff\" ..." << endl;
- writeImages(montage.begin(),montage.end(),"demo_out.miff");
+ writeImages(montage.begin(),montage.end(),"demo_out_%d.miff");
// Uncomment following lines to display image to screen
// cout << "Display image..." << endl;