diff --git a/src/collector.ml b/src/collector.ml
index 1b45212..ccde562 100644
--- a/src/collector.ml
+++ b/src/collector.ml
@@ -19,14 +19,7 @@ module type S = sig
     span
 
   val exit_span : span -> unit
-
-  val message :
-    ?__FUNCTION__:string ->
-    __FILE__:string ->
-    __LINE__:int ->
-    data:(string * user_data) list ->
-    string ->
-    unit
+  val message : ?span:span -> data:(string * user_data) list -> string -> unit
 
   val name_thread : string -> unit
   (** Give a name to the current thread *)
diff --git a/src/tef/trace_tef.ml b/src/tef/trace_tef.ml
index 59d37b5..7497175 100644
--- a/src/tef/trace_tef.ml
+++ b/src/tef/trace_tef.ml
@@ -293,7 +293,7 @@ let collector ~out () : collector =
       let time_us = now_us () in
       B_queue.push events (E_exit_span { id = span; time_us })
 
-    let message ?__FUNCTION__:_ ~__FILE__:_ ~__LINE__:_ ~data msg : unit =
+    let message ?span:_ ~data msg : unit =
       let time_us = now_us () in
       let tid = get_tid_ () in
       B_queue.push events
diff --git a/src/trace.ml b/src/trace.ml
index 4843e21..ae2c7ab 100644
--- a/src/trace.ml
+++ b/src/trace.ml
@@ -50,18 +50,17 @@ let[@inline] with_span ?__FUNCTION__ ~__FILE__ ~__LINE__ ?data name f =
     with_span_collector_ collector ?__FUNCTION__ ~__FILE__ ~__LINE__ ?data name
       f
 
-let message_collector_ (module C : Collector.S) ?__FUNCTION__ ~__FILE__
-    ~__LINE__ ?(data = fun () -> []) msg : unit =
+let message_collector_ (module C : Collector.S) ?span ?(data = fun () -> []) msg
+    : unit =
   let data = data () in
-  C.message ?__FUNCTION__ ~__FILE__ ~__LINE__ ~data msg
+  C.message ?span ~data msg
 
-let[@inline] message ?__FUNCTION__ ~__FILE__ ~__LINE__ ?data msg : unit =
+let[@inline] message ?span ?data msg : unit =
   match A.get collector with
   | None -> ()
-  | Some coll ->
-    message_collector_ coll ?__FUNCTION__ ~__FILE__ ~__LINE__ ?data msg
+  | Some coll -> message_collector_ coll ?span ?data msg
 
-let messagef ?__FUNCTION__ ~__FILE__ ~__LINE__ ?data k =
+let messagef ?span ?data k =
   match A.get collector with
   | None -> ()
   | Some (module C) ->
@@ -73,7 +72,7 @@ let messagef ?__FUNCTION__ ~__FILE__ ~__LINE__ ?data k =
               | None -> []
               | Some f -> f ()
             in
-            C.message ?__FUNCTION__ ~__FILE__ ~__LINE__ ~data str)
+            C.message ?span ~data str)
           fmt)
 
 let set_thread_name name : unit =
diff --git a/src/trace.mli b/src/trace.mli
index 5222614..17a1c56 100644
--- a/src/trace.mli
+++ b/src/trace.mli
@@ -31,9 +31,7 @@ val with_span :
   'a
 
 val message :
-  ?__FUNCTION__:string ->
-  __FILE__:string ->
-  __LINE__:int ->
+  ?span:span ->
   ?data:(unit -> (string * user_data) list) ->
   string ->
   unit
@@ -41,9 +39,7 @@ val message :
 (* TODO: counter/plot/metric *)
 
 val messagef :
-  ?__FUNCTION__:string ->
-  __FILE__:string ->
-  __LINE__:int ->
+  ?span:span ->
   ?data:(unit -> (string * user_data) list) ->
   ((('a, Format.formatter, unit, unit) format4 -> 'a) -> unit) ->
   unit
diff --git a/test/t1.ml b/test/t1.ml
index d9656dc..e7920b3 100644
--- a/test/t1.ml
+++ b/test/t1.ml
@@ -5,7 +5,7 @@ let run () =
     Trace.with_span ~__FILE__ ~__LINE__ "outer.loop" @@ fun _sp ->
     for _j = 2 to 5 do
       Trace.with_span ~__FILE__ ~__LINE__ "inner.loop" @@ fun _sp ->
-      Trace.messagef ~__FILE__ ~__LINE__ (fun k -> k "hello %d %d" _i _j)
+      Trace.messagef (fun k -> k "hello %d %d" _i _j)
     done
   done