diff --git a/pkgs/applications/science/logic/beluga/default.nix b/pkgs/applications/science/logic/beluga/default.nix
index 66cfd306128..9af0cd694b7 100644
--- a/pkgs/applications/science/logic/beluga/default.nix
+++ b/pkgs/applications/science/logic/beluga/default.nix
@@ -14,7 +14,7 @@ ocamlPackages.buildDunePackage rec {
   useDune2 = true;
 
   buildInputs = with ocamlPackages; [
-    gen sedlex_2 ocaml_extlib dune-build-info linenoise
+    gen sedlex ocaml_extlib dune-build-info linenoise
   ];
 
   postPatch = ''
diff --git a/pkgs/development/compilers/fstar/default.nix b/pkgs/development/compilers/fstar/default.nix
index eb81efe2de0..a269edd6668 100644
--- a/pkgs/development/compilers/fstar/default.nix
+++ b/pkgs/development/compilers/fstar/default.nix
@@ -33,7 +33,7 @@ stdenv.mkDerivation rec {
     fileutils
     menhirLib
     pprint
-    sedlex_2
+    sedlex
     ppxlib
     ppx_deriving
     ppx_deriving_yojson
diff --git a/pkgs/development/compilers/haxe/default.nix b/pkgs/development/compilers/haxe/default.nix
index 4ac022be6a9..c362abbc1f6 100644
--- a/pkgs/development/compilers/haxe/default.nix
+++ b/pkgs/development/compilers/haxe/default.nix
@@ -6,7 +6,7 @@ let
     then with ocaml-ng.ocamlPackages_4_12; [
       ocaml
       findlib
-      sedlex_2
+      sedlex
       xml-light
       ptmap
       camlp5
@@ -18,7 +18,7 @@ let
     then with ocaml-ng.ocamlPackages_4_10; [
       ocaml
       findlib
-      sedlex_2
+      sedlex
       xml-light
       ptmap
       camlp5
diff --git a/pkgs/development/ocaml-modules/higlo/default.nix b/pkgs/development/ocaml-modules/higlo/default.nix
index 19b2fa8942a..87a4186a68c 100644
--- a/pkgs/development/ocaml-modules/higlo/default.nix
+++ b/pkgs/development/ocaml-modules/higlo/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildDunePackage, fetchFromGitLab, sedlex_2, xtmpl }:
+{ lib, buildDunePackage, fetchFromGitLab, sedlex, xtmpl }:
 
 buildDunePackage rec {
   pname = "higlo";
@@ -12,7 +12,7 @@ buildDunePackage rec {
     sha256 = "sha256:09hsbwy5asacgh4gdj0vjpy4kzfnq3qji9szbsbyswsf1nbyczir";
   };
 
-  propagatedBuildInputs = [ sedlex_2 xtmpl ];
+  propagatedBuildInputs = [ sedlex xtmpl ];
 
   meta = with lib; {
     description = "OCaml library for syntax highlighting";
diff --git a/pkgs/development/ocaml-modules/iri/default.nix b/pkgs/development/ocaml-modules/iri/default.nix
index 6a00fb453df..22f10697586 100644
--- a/pkgs/development/ocaml-modules/iri/default.nix
+++ b/pkgs/development/ocaml-modules/iri/default.nix
@@ -1,5 +1,5 @@
 { lib, buildDunePackage, fetchFromGitLab
-, sedlex_2, uunf, uutf
+, sedlex, uunf, uutf
 }:
 
 buildDunePackage rec {
@@ -15,7 +15,7 @@ buildDunePackage rec {
     sha256 = "sha256:0zk8nnwcyljkc1a556byncv6cn1vqhk4267z1lm15flh1k7chyax";
   };
 
-  propagatedBuildInputs = [ sedlex_2 uunf uutf ];
+  propagatedBuildInputs = [ sedlex uunf uutf ];
 
   meta = {
     description = "IRI (RFC3987) native OCaml implementation";
diff --git a/pkgs/development/ocaml-modules/piqi/default.nix b/pkgs/development/ocaml-modules/piqi/default.nix
index 45d65a5be04..f9eb09987fb 100644
--- a/pkgs/development/ocaml-modules/piqi/default.nix
+++ b/pkgs/development/ocaml-modules/piqi/default.nix
@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchFromGitHub, ocaml, findlib, which, sedlex_2, easy-format, xmlm, base64 }:
+{ lib, stdenv, fetchFromGitHub, ocaml, findlib, which, sedlex, easy-format, xmlm, base64 }:
 
 stdenv.mkDerivation rec {
   version = "0.6.15";
@@ -13,7 +13,7 @@ stdenv.mkDerivation rec {
   };
 
   nativeBuildInputs = [ ocaml findlib which ];
-  propagatedBuildInputs = [ sedlex_2 xmlm easy-format base64 ];
+  propagatedBuildInputs = [ sedlex xmlm easy-format base64 ];
 
   strictDeps = true;
 
diff --git a/pkgs/development/ocaml-modules/sedlex/2.nix b/pkgs/development/ocaml-modules/sedlex/default.nix
similarity index 100%
rename from pkgs/development/ocaml-modules/sedlex/2.nix
rename to pkgs/development/ocaml-modules/sedlex/default.nix
diff --git a/pkgs/development/ocaml-modules/xtmpl/default.nix b/pkgs/development/ocaml-modules/xtmpl/default.nix
index 7c2f0a01e53..6b4771fe1ff 100644
--- a/pkgs/development/ocaml-modules/xtmpl/default.nix
+++ b/pkgs/development/ocaml-modules/xtmpl/default.nix
@@ -1,4 +1,4 @@
-{ lib, buildDunePackage, fetchFromGitLab, iri, re, sedlex_2, uutf }:
+{ lib, buildDunePackage, fetchFromGitLab, iri, re, sedlex, uutf }:
 
 buildDunePackage rec {
   pname = "xtmpl";
@@ -12,7 +12,7 @@ buildDunePackage rec {
     sha256 = "sha256:0vwj0aayg60wm98d91fg3hmj90730liljy4cn8771dpxvz8m07bw";
   };
 
-  propagatedBuildInputs = [ iri re sedlex_2 uutf ];
+  propagatedBuildInputs = [ iri re sedlex uutf ];
 
   meta = with lib; {
     description = "XML templating library for OCaml";
diff --git a/pkgs/development/tools/analysis/flow/default.nix b/pkgs/development/tools/analysis/flow/default.nix
index 2325ab03c96..37241a95340 100644
--- a/pkgs/development/tools/analysis/flow/default.nix
+++ b/pkgs/development/tools/analysis/flow/default.nix
@@ -18,7 +18,7 @@ stdenv.mkDerivation rec {
     install -Dm644 resources/shell/bash-completion $out/share/bash-completion/completions/flow
   '';
 
-  buildInputs = (with ocamlPackages; [ ocaml findlib ocamlbuild ocaml-migrate-parsetree-2 dtoa core_kernel sedlex_2 ocaml_lwt lwt_log lwt_ppx ppx_deriving ppx_gen_rec visitors wtf8 ])
+  buildInputs = (with ocamlPackages; [ ocaml findlib ocamlbuild ocaml-migrate-parsetree-2 dtoa core_kernel sedlex ocaml_lwt lwt_log lwt_ppx ppx_deriving ppx_gen_rec visitors wtf8 ])
     ++ lib.optionals stdenv.isDarwin [ CoreServices ];
 
   meta = with lib; {
diff --git a/pkgs/tools/audio/liquidsoap/full.nix b/pkgs/tools/audio/liquidsoap/full.nix
index 1c52e6796b7..94cc353dd1c 100644
--- a/pkgs/tools/audio/liquidsoap/full.nix
+++ b/pkgs/tools/audio/liquidsoap/full.nix
@@ -59,7 +59,7 @@ stdenv.mkDerivation {
       ocamlPackages.xmlm ocamlPackages.ocaml_pcre
       ocamlPackages.camomile
       ocamlPackages.fdkaac
-      ocamlPackages.srt ocamlPackages.sedlex_2 ocamlPackages.menhir ocamlPackages.menhirLib
+      ocamlPackages.srt ocamlPackages.sedlex ocamlPackages.menhir ocamlPackages.menhirLib
     ];
 
   hardeningDisable = [ "format" "fortify" ];
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index ef3d6abc9ea..cc8fc806324 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -1320,7 +1320,7 @@ let
 
     safepass = callPackage ../development/ocaml-modules/safepass { };
 
-    sedlex_2 = callPackage ../development/ocaml-modules/sedlex/2.nix { };
+    sedlex = callPackage ../development/ocaml-modules/sedlex { };
 
     semaphore-compat = callPackage ../development/ocaml-modules/semaphore-compat { };