diff --git a/dune-project b/dune-project
index 78ee148..25b6175 100644
--- a/dune-project
+++ b/dune-project
@@ -44,7 +44,7 @@
   ; we use __FUNCTION__
   (ppxlib
    (and
-    (>= 0.28)
+    (>= 0.37)
     (< 0.38)))
   (trace
    (= :version))
diff --git a/ppx_trace.opam b/ppx_trace.opam
index 6d14849..51fa2d1 100644
--- a/ppx_trace.opam
+++ b/ppx_trace.opam
@@ -10,7 +10,7 @@ homepage: "https://github.com/c-cube/ocaml-trace"
 bug-reports: "https://github.com/c-cube/ocaml-trace/issues"
 depends: [
   "ocaml" {>= "4.12"}
-  "ppxlib" {>= "0.28" & < "0.38"}
+  "ppxlib" {>= "0.37" & < "0.38"}
   "trace" {= version}
   "trace-tef" {= version & with-test}
   "dune" {>= "2.9"}