diff --git a/examples/04_more_image_formats.cpp b/examples/04_more_image_formats.cpp
index 5d23fcdcb3642c9a3859efd61b93d60765d51a0f..71dbc93497494c65aaeff08e5f65caf64cfa397d 100644
--- a/examples/04_more_image_formats.cpp
+++ b/examples/04_more_image_formats.cpp
@@ -139,7 +139,7 @@ auto picopng_load_image(const char* filename)
 	auto png = simple::file::dump( simple::file::bropex(filename) );
 
 	std::vector<surface::byte> image_data;
-	simple::geom::vector<unsigned long> image_size;
+	simple::geom::vector<unsigned long,2> image_size;
 	int picopng_result = decodePNG(
 			image_data, image_size.x(), image_size.y(),
 			reinterpret_cast<unsigned char*>(png.data()), png.size());