diff --git a/src/ppx/ppx_trace.ml b/src/ppx/ppx_trace.ml
index 9601005..e088cf9 100644
--- a/src/ppx/ppx_trace.ml
+++ b/src/ppx/ppx_trace.ml
@@ -53,9 +53,9 @@ let expand_top_let ~ctxt rec_flag (vbs : _ list) =
             Trace_core.enter_span ~__FILE__ ~__LINE__ __FUNCTION__
           in
           try
-            let res = [%e e] in
+            let _trace_ppx_res = [%e e] in
             Trace_core.exit_span _trace_span;
-            res
+            __trace_ppx_res
           with exn ->
             Trace_core.exit_span _trace_span;
             raise exn]