diff --git a/pkgs/development/ocaml-modules/dose3/default.nix b/pkgs/development/ocaml-modules/dose3/default.nix
index 70994c47cca7..e271ea128c7f 100644
--- a/pkgs/development/ocaml-modules/dose3/default.nix
+++ b/pkgs/development/ocaml-modules/dose3/default.nix
@@ -42,7 +42,8 @@ buildDunePackage rec {
   checkInputs = [
     ounit
   ];
-  doCheck = lib.versionAtLeast ocaml.version "4.08";
+  # Check are not compatible with re ≥ 1.12
+  doCheck = lib.versionAtLeast ocaml.version "4.08" && !lib.versionAtLeast ocaml.version "4.12";
 
   meta = with lib; {
     description = "Dose library (part of Mancoosi tools)";
diff --git a/pkgs/development/ocaml-modules/re/default.nix b/pkgs/development/ocaml-modules/re/default.nix
index badee9a3c91d..54bd7a664ae2 100644
--- a/pkgs/development/ocaml-modules/re/default.nix
+++ b/pkgs/development/ocaml-modules/re/default.nix
@@ -4,20 +4,26 @@
   buildDunePackage,
   ocaml,
   ounit,
+  ounit2,
   seq,
 }:
 
 let
   version_sha =
-    if lib.versionAtLeast ocaml.version "4.08" then
+    if lib.versionAtLeast ocaml.version "4.12" then
+      {
+        version = "1.12.0";
+        hash = "sha256-oB8r8i9ywvSrq9jT52NeNcG/a8WkGtbVoAdFTdq60dQ=";
+      }
+    else if lib.versionAtLeast ocaml.version "4.08" then
       {
         version = "1.11.0";
-        sha256 = "sha256-AfwkR4DA9r5yrnlrH7dQ82feGGJP110H7nl4LtbfjU8=";
+        hash = "sha256-AfwkR4DA9r5yrnlrH7dQ82feGGJP110H7nl4LtbfjU8=";
       }
     else
       {
         version = "1.9.0";
-        sha256 = "1gas4ky49zgxph3870nffzkr6y41kkpqp4nj38pz1gh49zcf12aj";
+        hash = "sha256:1gas4ky49zgxph3870nffzkr6y41kkpqp4nj38pz1gh49zcf12aj";
       };
 in
 
@@ -29,12 +35,12 @@ buildDunePackage rec {
 
   src = fetchurl {
     url = "https://github.com/ocaml/ocaml-re/releases/download/${version}/re-${version}.tbz";
-    sha256 = version_sha.sha256;
+    inherit (version_sha) hash;
   };
 
-  buildInputs = lib.optional doCheck ounit;
   propagatedBuildInputs = [ seq ];
   doCheck = lib.versionAtLeast ocaml.version "4.08";
+  checkInputs = [ (if lib.versionAtLeast version "1.12" then ounit2 else ounit) ];
 
   meta = {
     homepage = "https://github.com/ocaml/ocaml-re";