diff --git a/CHANGES.md b/CHANGES.md
index 5abef64..c07ebee 100644
--- a/CHANGES.md
+++ b/CHANGES.md
@@ -1,3 +1,8 @@
+1.0.1
+-----
+
+- Fix compat with OCaml 4.04
+
 1.0.0
 -----
 
diff --git a/Makefile b/Makefile
index b3f6fce..3417e11 100644
--- a/Makefile
+++ b/Makefile
@@ -17,4 +17,7 @@ reinstall: uninstall install
 clean:
 	dune clean
 
+all-supported-ocaml-versions:
+	dune runtest --workspace dune-workspace.dev
+
 .PHONY: default install uninstall reinstall clean test
diff --git a/dune-workspace.dev b/dune-workspace.dev
new file mode 100644
index 0000000..d385721
--- /dev/null
+++ b/dune-workspace.dev
@@ -0,0 +1,4 @@
+(lang dune 1.0)
+
+;; This file is used by `make all-supported-ocaml-versions`
+(context (opam (switch 4.04.2)))
diff --git a/src/pp.ml b/src/pp.ml
index 96cc7ec..a8398d7 100644
--- a/src/pp.ml
+++ b/src/pp.ml
@@ -1,5 +1,5 @@
-module List = Stdlib.ListLabels
-module String = Stdlib.StringLabels
+module List = ListLabels
+module String = StringLabels
 
 type +'a t =
   | Nop
diff --git a/test/tests.ml b/test/tests.ml
index 8ad52ee..a04fbc8 100644
--- a/test/tests.ml
+++ b/test/tests.ml
@@ -163,7 +163,8 @@ let%expect_test _ =
        ++ Pp.cut
        ++ Pp.box (Pp.text "Here are a few things you can do:")
        ++ Pp.cut
-       ++ Pp.enumerate ~f:Fun.id
+       ++ Pp.enumerate
+            ~f:(fun x -> x)
             [ Pp.text
                 "read the documentation, double check the way you are using \
                  this software to make sure you are not doing something wrong, \
@@ -180,7 +181,8 @@ let%expect_test _ =
                    ; "clear your head and try again"
                    ]
             ] ));
-  [%expect {|
+  [%expect
+    {|
     Error: something went wrong!
     Here are a few things you can do:
     - read the documentation, double check the way you are using this software to