diff --git a/cmdlang-to-base.opam b/cmdlang-to-base.opam
index 0505216..e475bb3 100644
--- a/cmdlang-to-base.opam
+++ b/cmdlang-to-base.opam
@@ -21,6 +21,7 @@ depends: [
   "ppx_let" {>= "v0.17" & < "v0.18"}
   "ppx_sexp_conv" {>= "v0.17" & < "v0.18"}
   "ppx_sexp_value" {>= "v0.17" & < "v0.18"}
+  "ppxlib" {>= "0.33"}
   "stdio" {>= "v0.17" & < "v0.18"}
   "odoc" {with-doc}
 ]
diff --git a/dune-project b/dune-project
index edb75b2..b5e5d9d 100644
--- a/dune-project
+++ b/dune-project
@@ -72,6 +72,8 @@
    (and
     (>= v0.17)
     (< v0.18)))
+  (ppxlib
+   (>= 0.33))
   (stdio
    (and
     (>= v0.17)