diff --git a/sledge/dune-common.in b/sledge/dune-common.in
index 2720e9776..8de366914 100644
--- a/sledge/dune-common.in
+++ b/sledge/dune-common.in
@@ -37,7 +37,6 @@ let flags exe_or_lib deps =
       (ocamlopt_flags (%s))
       (preprocess
        (staged_pps
-         ppx_import
          ppx_compare
          ppx_custom_printf
          ppx_expect
diff --git a/sledge/sledge.opam b/sledge/sledge.opam
index 579ea9236..73dd10c35 100644
--- a/sledge/sledge.opam
+++ b/sledge/sledge.opam
@@ -21,7 +21,6 @@ depends: [
   "dune-build-info"
   "llvm" {= "8.0.0"}
   "ppx_compare"
-  "ppx_import"
   "ppx_hash"
   "shexp"
   "yojson"
diff --git a/sledge/src/domain/itv.ml b/sledge/src/domain/itv.ml
index e1d68955c..2646c8094 100644
--- a/sledge/src/domain/itv.ml
+++ b/sledge/src/domain/itv.ml
@@ -10,7 +10,9 @@
 open Apron
 open Option.Let_syntax
 
-type apron_typ = [%import: Apron.Texpr0.typ] [@@deriving equal]
+let equal_apron_typ =
+  (* Apron.Texpr1.typ is a sum of nullary constructors *)
+  Poly.equal
 
 (** Apron-managed map from variables to intervals *)
 type t = Box.t Abstract1.t
diff --git a/sledge/src/llair/frontend.ml b/sledge/src/llair/frontend.ml
index b3438d453..13d0319fd 100644
--- a/sledge/src/llair/frontend.ml
+++ b/sledge/src/llair/frontend.ml
@@ -15,16 +15,6 @@ 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 =
@@ -84,8 +74,7 @@ let ( (scan_names_and_locs : Llvm.llmodule -> unit)
       | ConstantExpr -> None
       | ConstantPointerNull -> None
       | _ ->
-          warn "Unexpected type %a of llv, might crash: %a" pp_llvaluekind
-            (Llvm.classify_value llv) pp_llvalue llv () ;
+          warn "Unexpected type of llv, might crash: %a" pp_llvalue llv () ;
           Some (`Mod (Llvm.global_parent llv))
     in
     match maybe_scope with
@@ -494,7 +483,7 @@ and xlate_opcode : x -> Llvm.llvalue -> Llvm.Opcode.t -> Exp.t =
     let rand = Llvm.operand llv 0 in
     let src = xlate_type x (Llvm.type_of rand) in
     let arg = xlate_value x rand in
-    match opcode with
+    match (opcode : Llvm.Opcode.t) with
     | Trunc -> Exp.signed (Typ.bit_size_of dst) arg ~to_:dst
     | SExt -> Exp.signed (Typ.bit_size_of src) arg ~to_:dst
     | ZExt -> Exp.unsigned (Typ.bit_size_of src) arg ~to_:dst
@@ -502,7 +491,7 @@ and xlate_opcode : x -> Llvm.llvalue -> Llvm.Opcode.t -> Exp.t =
     | FPToUI | FPToSI | UIToFP | SIToFP | FPTrunc | FPExt | PtrToInt
      |IntToPtr | BitCast | AddrSpaceCast ->
         Exp.convert src ~to_:dst arg
-    | _ -> fail "convert: %a" pp_llopcode opcode ()
+    | _ -> fail "convert: %a" pp_llvalue llv ()
   in
   let binary (mk : ?typ:_ -> _) =
     Lazy.force check_vector ;
@@ -855,7 +844,7 @@ let rec xlate_func_name x llv =
   | GlobalIFunc -> todo "ifunc: %a" pp_llvalue llv ()
   | InlineAsm -> todo "inline asm: %a" pp_llvalue llv ()
   | ConstantPointerNull -> todo "call null: %a" pp_llvalue llv ()
-  | k -> todo "function kind %a in %a" pp_llvaluekind k pp_llvalue llv ()
+  | _ -> todo "function kind in %a" pp_llvalue llv ()
 
 let ignored_callees = Hash_set.create (module String)
 
@@ -931,8 +920,8 @@ let xlate_instr :
               todo "opcode kind in call instruction %a" pp_llvalue
                 maybe_llfunc () )
         | _ ->
-            todo "operand kind in call instruction %a" pp_llvaluekind
-              llfunc_valuekind ()
+            todo "operand kind in call instruction %a" pp_llvalue
+              maybe_llfunc ()
       in
       let fname = Llvm.value_name llfunc in
       let skip msg =