diff --git a/tests/emit1.ml b/tests/emit1.ml
index 6e42566b..76ddeb03 100644
--- a/tests/emit1.ml
+++ b/tests/emit1.ml
@@ -1,10 +1,13 @@
 
 module T = Opentelemetry
 
+let (let@) f x = f x
+
 let run () =
   Printf.printf "collector is on %S\n%!" (Opentelemetry_client_ocurl.get_url());
   let i = ref 0 in
   while true do
+    let@ (tr,sp) = T.Trace.with_ "loop" in
     Unix.sleepf 2.;
 
     let gc = Gc.stat() in
@@ -17,9 +20,14 @@ let run () =
 
     incr i;
 
-    (* allocate some stuff *)
-    let _arr = Sys.opaque_identity @@ Array.make (25 * 25551) 42.0 in
-    ignore _arr;
+    begin
+      let@ _ = T.Trace.with_ ~kind:T.Span.Span_kind_client
+          ~trace_id:tr ~parent:sp "alloc" in
+      (* allocate some stuff *)
+      let _arr = Sys.opaque_identity @@ Array.make (25 * 25551) 42.0 in
+      ignore _arr;
+      Unix.sleepf 0.1;
+  end;
   done
 
 let () =