diff --git a/examples/map-async/main.zig b/examples/map-async/main.zig
index 73293d0f..abda48da 100644
--- a/examples/map-async/main.zig
+++ b/examples/map-async/main.zig
@@ -4,6 +4,9 @@ const gpu = @import("gpu");
 
 pub const App = @This();
 
+// TODO: without a field in this struct, stage3 seems to think `*App` is a `*const App`
+unused: f32,
+
 const workgroup_size = 64;
 const buffer_size = 1000;