diff --git a/sledge/dune-common.in b/sledge/dune-common.in
index 82f250a1d..70aece458 100644
--- a/sledge/dune-common.in
+++ b/sledge/dune-common.in
@@ -34,7 +34,8 @@ let flags exe_or_lib deps =
       (ocamlc_flags (%s))
       (ocamlopt_flags (%s))
       (preprocess
-       (pps
+       (staged_pps
+         ppx_import
          ppx_compare
          ppx_custom_printf
          ppx_deriving_cmdliner
diff --git a/sledge/sledge.opam b/sledge/sledge.opam
index c80ff428c..5af7da2ea 100644
--- a/sledge/sledge.opam
+++ b/sledge/sledge.opam
@@ -21,6 +21,7 @@ depends: [
   "llvm" {= "8.0.0"}
   "ppx_compare"
   "ppx_deriving_cmdliner" {>= "0.4.2"}
+  "ppx_import"
   "ppx_hash"
   "shexp"
   "zarith"
diff --git a/sledge/src/llair/frontend.ml b/sledge/src/llair/frontend.ml
index 25968b7d4..fb21536c4 100644
--- a/sledge/src/llair/frontend.ml
+++ b/sledge/src/llair/frontend.ml
@@ -15,6 +15,16 @@ let pp_llvalue fs t = Format.pp_print_string fs (Llvm.string_of_llvalue t)
 let pp_llblock fs t =
   Format.pp_print_string fs (Llvm.string_of_llvalue (Llvm.value_of_block t))
 
+type lllinkage = [%import: Llvm.Linkage.t] [@@deriving sexp]
+type llopcode = [%import: Llvm.Opcode.t] [@@deriving sexp]
+
+type llvaluekind = [%import: (Llvm.ValueKind.t[@with Opcode.t := llopcode])]
+[@@deriving sexp]
+
+let _pp_lllinkage fs l = Sexp.pp_hum fs (sexp_of_lllinkage l)
+let _pp_llopcode fs l = Sexp.pp_hum fs (sexp_of_llopcode l)
+let _pp_llvaluekind fs l = Sexp.pp_hum fs (sexp_of_llvaluekind l)
+
 exception Invalid_llvm of string
 
 let invalid_llvm : string -> 'a =