diff --git a/iter.opam b/iter.opam
index 10c495a..81cb36f 100644
--- a/iter.opam
+++ b/iter.opam
@@ -11,12 +11,8 @@ build: [
   ["dune" "runtest" "-p" name "-j" jobs] {with-test & arch != "arm32" & arch != "x86_32"}
 ]
 depends: [
-  "base-bytes"
-  "result"
-  "seq"
-  "ocaml" { >= "4.03.0" }
+  "ocaml" { >= "4.08.0" }
   "dune" { >= "2.0" }
-  "dune-configurator"
   "qcheck-core" {with-test}
   "ounit2" {with-test}
   "mdx" {with-test & >= "1.3" }
diff --git a/src/Iter.ml b/src/Iter.ml
index 3d3642b..7e1d2ad 100644
--- a/src/Iter.ml
+++ b/src/Iter.ml
@@ -1,9 +1,5 @@
 (* This file is free software, part of iter. See file "license" for more details. *)
 
-(** {1 Simple and Efficient Iterators} *)
-
-open Iter_shims_
-
 type 'a t = ('a -> unit) -> unit
 (** Iter abstract iterator type *)
 
diff --git a/src/bigarray/IterBigarray.ml b/src/bigarray/IterBigarray.ml
index b6745d0..1ad0806 100644
--- a/src/bigarray/IterBigarray.ml
+++ b/src/bigarray/IterBigarray.ml
@@ -2,7 +2,8 @@
 
 (** {1 Interface and Helpers for bigarrays} *)
 
-open! IterBigarrayShims_
+let bigarray_map_file fd ty lay b len =
+  Unix.map_file fd ty lay b [| len |] |> Bigarray.array1_of_genarray
 
 let of_bigarray b yield =
   let len = Bigarray.Array1.dim b in
diff --git a/src/bigarray/dune b/src/bigarray/dune
index f867621..1924c28 100644
--- a/src/bigarray/dune
+++ b/src/bigarray/dune
@@ -2,19 +2,6 @@
  (name iter_bigarray)
  (public_name iter.bigarray)
  (libraries iter bigarray unix)
- (modules IterBigarray IterBigarrayShims_)
+ (modules IterBigarray)
  (wrapped false)
  (optional))
-
-(executable
- (name mkshims)
- (modules mkshims)
- (libraries dune.configurator))
-
-(rule
- (targets IterBigarrayShims_.ml)
- (deps mkshims.exe)
- (action
-  (with-stdout-to
-   %{targets}
-   (run ./mkshims.exe))))
diff --git a/src/bigarray/mkshims.ml b/src/bigarray/mkshims.ml
deleted file mode 100644
index 80a7918..0000000
--- a/src/bigarray/mkshims.ml
+++ /dev/null
@@ -1,21 +0,0 @@
-module C = Configurator.V1
-
-let shims_pre_408 =
-  "\nopen! Bigarray\nlet bigarray_map_file = Bigarray.Array1.map_file\n"
-
-let shims_post_408 =
-  "\n\
-   let bigarray_map_file fd ty lay b len =\n\
-  \  Unix.map_file fd ty lay b [| len |] |> Bigarray.array1_of_genarray\n"
-
-let () =
-  C.main ~name:"mkshims" (fun c ->
-      let version = C.ocaml_config_var_exn c "version" in
-      let major, minor =
-        Scanf.sscanf version "%u.%u" (fun maj min -> maj, min)
-      in
-      print_endline
-        (if (major, minor) >= (4, 8) then
-          shims_post_408
-        else
-          shims_pre_408))
diff --git a/src/dune b/src/dune
index b0c45eb..6c49399 100644
--- a/src/dune
+++ b/src/dune
@@ -1,21 +1,9 @@
-(executable
- (name mkshims)
- (modules mkshims)
- (libraries dune.configurator))
-
-(rule
- (targets Iter_shims_.ml)
- (deps mkshims.exe)
- (action
-  (with-stdout-to
-   %{targets}
-   (run ./mkshims.exe))))
 
 (library
  (name iter)
  (public_name iter)
  (wrapped false)
- (modules Iter IterLabels Iter_shims_)
+ (modules Iter IterLabels)
  (flags :standard -w +a -warn-error -a+8 -nolabels)
  (libraries bytes result seq))
 
diff --git a/src/mkshims.ml b/src/mkshims.ml
deleted file mode 100644
index c278783..0000000
--- a/src/mkshims.ml
+++ /dev/null
@@ -1,16 +0,0 @@
-module C = Configurator.V1
-
-let shims_pre_408 = "module Stdlib = Pervasives"
-let shims_post_408 = "module Stdlib = Stdlib"
-
-let () =
-  C.main ~name:"mkshims" (fun c ->
-      let version = C.ocaml_config_var_exn c "version" in
-      let major, minor =
-        Scanf.sscanf version "%u.%u" (fun maj min -> maj, min)
-      in
-      print_endline
-        (if (major, minor) >= (4, 8) then
-          shims_post_408
-        else
-          shims_pre_408))