diff --git a/examples/cloud.cpp b/examples/cloud.cpp
index 3d70dac0..af5994ba 100644
--- a/examples/cloud.cpp
+++ b/examples/cloud.cpp
@@ -241,6 +241,8 @@ struct cloud_app
 
 			pcg::fractal<pcg::perlin<float, 3>> perlin(std::move(grad), std::move(weights));
 
+			// can't use template argument deduction for first argument due to gcc bug
+			// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89062
 			geom::gradient<float> g(std::make_pair(0.2f, 0.f), geom::easing_type::cubic, std::pair{0.4f, max_density});
 
 			util::array<std::uint8_t, 3> cloud_data({cloud_size[0], cloud_size[1], cloud_size[2]});