diff --git a/pkgs/development/ocaml-modules/async_extra/default.nix b/pkgs/development/ocaml-modules/async-extra/default.nix
similarity index 67%
rename from pkgs/development/ocaml-modules/async_extra/default.nix
rename to pkgs/development/ocaml-modules/async-extra/default.nix
index 2d1e1dea69cc..567562dcf28d 100644
--- a/pkgs/development/ocaml-modules/async_extra/default.nix
+++ b/pkgs/development/ocaml-modules/async-extra/default.nix
@@ -1,9 +1,9 @@
-{stdenv, buildOcaml, fetchurl, async_kernel, async_unix,
- bin_prot, core, custom_printf, fieldslib, herelib, pa_ounit,
- pipebang, pa_test, sexplib}:
+{stdenv, buildOcaml, fetchurl, async-kernel, async-unix,
+ bin-prot, core, custom-printf, fieldslib, herelib, pa-ounit,
+ pipebang, pa-test, sexplib}:
 
 buildOcaml rec {
-  name = "async_extra";
+  name = "async-extra";
   version = "112.24.00";
 
   minimumSupportedOcamlVersion = "4.02";
@@ -13,8 +13,8 @@ buildOcaml rec {
     sha256 = "51f6f67a9ad56fe5dcf09faeeca6ec2fea53a7a975a72bc80504b90841212e28";
   };
 
-  buildInputs = [ pa_test pa_ounit ];
-  propagatedBuildInputs = [ async_kernel async_unix core bin_prot custom_printf
+  buildInputs = [ pa-test pa-ounit ];
+  propagatedBuildInputs = [ async-kernel async-unix core bin-prot custom-printf
                             fieldslib herelib pipebang sexplib ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/async_find/default.nix b/pkgs/development/ocaml-modules/async-find/default.nix
similarity index 96%
rename from pkgs/development/ocaml-modules/async_find/default.nix
rename to pkgs/development/ocaml-modules/async-find/default.nix
index ae10e931ce25..4c12c994f8d1 100644
--- a/pkgs/development/ocaml-modules/async_find/default.nix
+++ b/pkgs/development/ocaml-modules/async-find/default.nix
@@ -1,7 +1,7 @@
 {stdenv, buildOcaml, fetchurl, async, core, sexplib}:
 
 buildOcaml rec {
-  name = "async_find";
+  name = "async-find";
   version = "111.28.00";
 
   minimumSupportedOcamlVersion = "4.02";
diff --git a/pkgs/development/ocaml-modules/async_kernel/default.nix b/pkgs/development/ocaml-modules/async-kernel/default.nix
similarity index 72%
rename from pkgs/development/ocaml-modules/async_kernel/default.nix
rename to pkgs/development/ocaml-modules/async-kernel/default.nix
index 8c0d8d7c851e..7e5db2e2c3e5 100644
--- a/pkgs/development/ocaml-modules/async_kernel/default.nix
+++ b/pkgs/development/ocaml-modules/async-kernel/default.nix
@@ -1,9 +1,9 @@
-{stdenv, buildOcaml, fetchurl, core_kernel,
- bin_prot, fieldslib, pa_ounit, pa_test,
+{stdenv, buildOcaml, fetchurl, core-kernel,
+ bin-prot, fieldslib, pa-ounit, pa-test,
  sexplib, herelib}:
 
 buildOcaml rec {
-  name = "async_kernel";
+  name = "async-kernel";
   version = "112.24.00";
 
   minimumSupportedOcamlVersion = "4.02";
@@ -13,8 +13,8 @@ buildOcaml rec {
     sha256 = "95caf4249b55c5a6b38da56e314845e9ea9a0876eedd4cf0ddcb6c8dd660c6a0";
   };
 
-  buildInputs = [ pa_test pa_ounit ];
-  propagatedBuildInputs = [ core_kernel bin_prot fieldslib herelib sexplib ];
+  buildInputs = [ pa-test pa-ounit ];
+  propagatedBuildInputs = [ core-kernel bin-prot fieldslib herelib sexplib ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async_kernel;
diff --git a/pkgs/development/ocaml-modules/async_shell/default.nix b/pkgs/development/ocaml-modules/async-shell/default.nix
similarity index 77%
rename from pkgs/development/ocaml-modules/async_shell/default.nix
rename to pkgs/development/ocaml-modules/async-shell/default.nix
index 75755833a5f5..6f863382bd2d 100644
--- a/pkgs/development/ocaml-modules/async_shell/default.nix
+++ b/pkgs/development/ocaml-modules/async-shell/default.nix
@@ -1,7 +1,7 @@
-{stdenv, buildOcaml, fetchurl, async, core, core_extended}:
+{stdenv, buildOcaml, fetchurl, async, core, core-extended}:
 
 buildOcaml rec {
-  name = "async_shell";
+  name = "async-shell";
   version = "109.28.03";
 
   minimumSupportedOcamlVersion = "4.02";
@@ -11,7 +11,7 @@ buildOcaml rec {
     sha256 = "0b4497bea9124c5a665ee58fb0a73c5cbf2f757479df902e6870627196e6c105";
   };
 
-  propagatedBuildInputs = [ async core core_extended ];
+  propagatedBuildInputs = [ async core core-extended ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async_shell;
diff --git a/pkgs/development/ocaml-modules/async_ssl/default.nix b/pkgs/development/ocaml-modules/async-ssl/default.nix
similarity index 86%
rename from pkgs/development/ocaml-modules/async_ssl/default.nix
rename to pkgs/development/ocaml-modules/async-ssl/default.nix
index 527d56ceaa01..49fd3033320e 100644
--- a/pkgs/development/ocaml-modules/async_ssl/default.nix
+++ b/pkgs/development/ocaml-modules/async-ssl/default.nix
@@ -1,5 +1,5 @@
 {stdenv, buildOcaml, fetchurl, async, comparelib, core, ctypes, openssl,
- fieldslib, herelib, pa_bench, pa_ounit, pipebang, pa_test, sexplib}:
+ fieldslib, herelib, pa-bench, pa-ounit, pipebang, pa-test, sexplib}:
 
 buildOcaml rec {
   name = "async_ssl";
@@ -12,8 +12,8 @@ buildOcaml rec {
     sha256 = "1b0bea92142eef11da6bf649bbe229bd4b8d9cc807303d8142406908c0d28c68";
   };
 
-  buildInputs = [ pa_bench pa_test ];
-  propagatedBuildInputs = [ ctypes async comparelib core fieldslib pa_ounit
+  buildInputs = [ pa-bench pa-test ];
+  propagatedBuildInputs = [ ctypes async comparelib core fieldslib pa-ounit
                             herelib pipebang sexplib openssl ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/async_unix/default.nix b/pkgs/development/ocaml-modules/async-unix/default.nix
similarity index 64%
rename from pkgs/development/ocaml-modules/async_unix/default.nix
rename to pkgs/development/ocaml-modules/async-unix/default.nix
index 81fbd6a99182..b8fe7bee2551 100644
--- a/pkgs/development/ocaml-modules/async_unix/default.nix
+++ b/pkgs/development/ocaml-modules/async-unix/default.nix
@@ -1,9 +1,9 @@
-{stdenv, buildOcaml, fetchurl, async_kernel,
- bin_prot, comparelib, core, fieldslib, herelib, pa_ounit,
- pipebang, pa_test, sexplib}:
+{stdenv, buildOcaml, fetchurl, async-kernel,
+ bin-prot, comparelib, core, fieldslib, herelib, pa-ounit,
+ pipebang, pa-test, sexplib}:
 
 buildOcaml rec {
-  name = "async_unix";
+  name = "async-unix";
   version = "112.24.00";
 
   minimumSupportedOcamlVersion = "4.02";
@@ -14,9 +14,9 @@ buildOcaml rec {
   };
 
   hasSharedObjects = true;
-  buildInputs = [ pa_ounit ];
-  propagatedBuildInputs = [ async_kernel core bin_prot comparelib
-                            fieldslib herelib pipebang pa_test sexplib ];
+  buildInputs = [ pa-ounit ];
+  propagatedBuildInputs = [ async-kernel core bin-prot comparelib
+                            fieldslib herelib pipebang pa-test sexplib ];
 
    meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async_unix;
diff --git a/pkgs/development/ocaml-modules/async/default.nix b/pkgs/development/ocaml-modules/async/default.nix
index 2b84519036c7..a813c3f45222 100644
--- a/pkgs/development/ocaml-modules/async/default.nix
+++ b/pkgs/development/ocaml-modules/async/default.nix
@@ -1,5 +1,5 @@
-{stdenv, buildOcaml, fetchurl, async_kernel,
- async_unix, async_extra, pa_ounit}:
+{stdenv, buildOcaml, fetchurl, async-kernel,
+ async-unix, async-extra, pa-ounit}:
 
 buildOcaml rec {
   name = "async";
@@ -12,7 +12,7 @@ buildOcaml rec {
     sha256 = "ecc4ca939ab098e689332921b110dbaacd06d9f8d8bf697023dfff3ca37dc1e9";
   };
 
-  propagatedBuildInputs = [ async_kernel async_unix async_extra pa_ounit ];
+  propagatedBuildInputs = [ async-kernel async-unix async-extra pa-ounit ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/async;
diff --git a/pkgs/development/ocaml-modules/bin_prot/default.nix b/pkgs/development/ocaml-modules/bin-prot/default.nix
similarity index 81%
rename from pkgs/development/ocaml-modules/bin_prot/default.nix
rename to pkgs/development/ocaml-modules/bin-prot/default.nix
index 4a2b9846271b..4f8c3181e238 100644
--- a/pkgs/development/ocaml-modules/bin_prot/default.nix
+++ b/pkgs/development/ocaml-modules/bin-prot/default.nix
@@ -1,7 +1,7 @@
-{stdenv, writeText, buildOcaml, fetchurl, type_conv}:
+{stdenv, writeText, buildOcaml, fetchurl, type-conv}:
 
 buildOcaml rec {
-  name = "bin_prot";
+  name = "bin-prot";
   version = "112.24.00";
 
   minimumSupportedOcamlVersion = "4.00";
@@ -11,7 +11,7 @@ buildOcaml rec {
     sha256 = "dc0c978a825c7c123990af3317637c218f61079e6f35dc878260651084f1adb4";
   };
 
-  propagatedBuildInputs = [ type_conv ];
+  propagatedBuildInputs = [ type-conv ];
 
   hasSharedObjects = true;
 
diff --git a/pkgs/development/ocaml-modules/cohttp/default.nix b/pkgs/development/ocaml-modules/cohttp/default.nix
index e219b59de5de..92690d96ffb6 100644
--- a/pkgs/development/ocaml-modules/cohttp/default.nix
+++ b/pkgs/development/ocaml-modules/cohttp/default.nix
@@ -1,6 +1,6 @@
 {stdenv, buildOcaml, fetchurl, cmdliner, re, uri, fieldslib, sexplib, conduit,
  stringext, base64, magic-mime, ounit, alcotest, lwt ? null,
- async ? null, async_ssl ? null}:
+ async ? null, async-ssl ? null}:
 
 buildOcaml rec {
   name = "cohttp";
@@ -16,7 +16,7 @@ buildOcaml rec {
   buildInputs = [ alcotest ];
   propagatedBuildInputs = [ cmdliner re uri fieldslib sexplib sexplib
                             conduit stringext base64 magic-mime ounit async
-                            async_ssl lwt ];
+                            async-ssl lwt ];
 
   buildFlags = "PREFIX=$(out)";
 
diff --git a/pkgs/development/ocaml-modules/comparelib/default.nix b/pkgs/development/ocaml-modules/comparelib/default.nix
index 950012158142..a4e125611945 100644
--- a/pkgs/development/ocaml-modules/comparelib/default.nix
+++ b/pkgs/development/ocaml-modules/comparelib/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, type_conv}:
+{stdenv, buildOcaml, fetchurl, type-conv}:
 
 buildOcaml rec {
   name = "comparelib";
@@ -11,7 +11,7 @@ buildOcaml rec {
     sha256 = "1075fb05e0d1e290f71ad0f6163f32b2cb4cebdc77568491c7eb38ba91f5db7e";
   };
 
-  propagatedBuildInputs = [ type_conv ];
+  propagatedBuildInputs = [ type-conv ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/comparelib;
diff --git a/pkgs/development/ocaml-modules/conduit/default.nix b/pkgs/development/ocaml-modules/conduit/default.nix
index dbb83f4c8cf0..2ea316462c26 100644
--- a/pkgs/development/ocaml-modules/conduit/default.nix
+++ b/pkgs/development/ocaml-modules/conduit/default.nix
@@ -1,5 +1,5 @@
 {stdenv, buildOcaml, fetchurl, sexplib, stringext, uri, cstruct, ipaddr,
- async ? null, async_ssl ? null, lwt ? null}:
+ async ? null, async-ssl ? null, lwt ? null}:
 
 buildOcaml rec {
   name = "conduit";
@@ -13,7 +13,7 @@ buildOcaml rec {
   propagatedBuildInputs = ([ sexplib stringext uri cstruct ipaddr ]
                             ++ stdenv.lib.optional (lwt != null) lwt
                             ++ stdenv.lib.optional (async != null) async
-                            ++ stdenv.lib.optional (async_ssl != null) async_ssl);
+                            ++ stdenv.lib.optional (async-ssl != null) async-ssl);
 
   meta = with stdenv.lib; {
     homepage = https://github.com/mirage/ocaml-conduit;
diff --git a/pkgs/development/ocaml-modules/core_extended/default.nix b/pkgs/development/ocaml-modules/core-extended/default.nix
similarity index 69%
rename from pkgs/development/ocaml-modules/core_extended/default.nix
rename to pkgs/development/ocaml-modules/core-extended/default.nix
index f311aae3d304..aa6741e6520f 100644
--- a/pkgs/development/ocaml-modules/core_extended/default.nix
+++ b/pkgs/development/ocaml-modules/core-extended/default.nix
@@ -1,8 +1,8 @@
-{stdenv, buildOcaml, fetchurl, bin_prot, comparelib, core, custom_printf,
- fieldslib, pa_bench, pa_ounit, pipebang, pa_test, textutils, re2, sexplib}:
+{stdenv, buildOcaml, fetchurl, bin-prot, comparelib, core, custom-printf,
+ fieldslib, pa-bench, pa-ounit, pipebang, pa-test, textutils, re2, sexplib}:
 
 buildOcaml rec {
-  name = "core_extended";
+  name = "core-extended";
   version = "112.24.00";
 
   minimumSupportedOcamlVersion = "4.02";
@@ -13,8 +13,8 @@ buildOcaml rec {
   };
 
   hasSharedObjects = true;
-  buildInputs = [ pa_bench pa_test pa_ounit ];
-  propagatedBuildInputs = [bin_prot comparelib core custom_printf fieldslib
+  buildInputs = [ pa-bench pa-test pa-ounit ];
+  propagatedBuildInputs = [bin-prot comparelib core custom-printf fieldslib
                            pipebang textutils re2 sexplib ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/core_kernel/default.nix b/pkgs/development/ocaml-modules/core-kernel/default.nix
similarity index 71%
rename from pkgs/development/ocaml-modules/core_kernel/default.nix
rename to pkgs/development/ocaml-modules/core-kernel/default.nix
index 0fed12b195d6..ee1a8b7a5bb6 100644
--- a/pkgs/development/ocaml-modules/core_kernel/default.nix
+++ b/pkgs/development/ocaml-modules/core-kernel/default.nix
@@ -1,10 +1,10 @@
-{stdenv, buildOcaml, fetchurl, type_conv,
- bin_prot, comparelib, custom_printf, enumerate,
- fieldslib, herelib, pa_bench, pa_test, pa_ounit,
+{stdenv, buildOcaml, fetchurl, type-conv,
+ bin-prot, comparelib, custom-printf, enumerate,
+ fieldslib, herelib, pa-bench, pa-test, pa-ounit,
  pipebang, sexplib, typerep, variantslib}:
 
 buildOcaml rec {
-  name = "core_kernel";
+  name = "core-kernel";
   version = "112.24.00";
 
   minimumSupportedOcamlVersion = "4.02";
@@ -16,8 +16,8 @@ buildOcaml rec {
 
   hasSharedObjects = true;
 
-  buildInputs = [ pa_test pa_ounit ];
-  propagatedBuildInputs = [ type_conv pa_bench bin_prot comparelib custom_printf
+  buildInputs = [ pa-test pa-ounit ];
+  propagatedBuildInputs = [ type-conv pa-bench bin-prot comparelib custom-printf
                             enumerate fieldslib herelib pipebang sexplib
                             typerep variantslib ];
 
diff --git a/pkgs/development/ocaml-modules/core/default.nix b/pkgs/development/ocaml-modules/core/default.nix
index 96fd80087d66..9cc03883932f 100644
--- a/pkgs/development/ocaml-modules/core/default.nix
+++ b/pkgs/development/ocaml-modules/core/default.nix
@@ -1,6 +1,6 @@
-{stdenv, buildOcaml, fetchurl, type_conv,
- core_kernel, bin_prot, comparelib, custom_printf, enumerate,
- fieldslib, herelib, pa_bench, pa_test, pa_ounit,
+{stdenv, buildOcaml, fetchurl, type-conv,
+ core-kernel, bin-prot, comparelib, custom-printf, enumerate,
+ fieldslib, herelib, pa-bench, pa-test, pa-ounit,
  pipebang, sexplib, typerep, variantslib}:
 
 buildOcaml rec {
@@ -16,9 +16,9 @@ buildOcaml rec {
 
   hasSharedObjects = true;
 
-  buildInputs = [ pa_bench pa_test pa_ounit ];
-  propagatedBuildInputs = [ type_conv core_kernel bin_prot comparelib
-                            custom_printf enumerate fieldslib herelib
+  buildInputs = [ pa-bench pa-test pa-ounit ];
+  propagatedBuildInputs = [ type-conv core-kernel bin-prot comparelib
+                            custom-printf enumerate fieldslib herelib
                             pipebang sexplib typerep variantslib ];
 
   meta = with stdenv.lib; {
diff --git a/pkgs/development/ocaml-modules/custom_printf/default.nix b/pkgs/development/ocaml-modules/custom-printf/default.nix
similarity index 75%
rename from pkgs/development/ocaml-modules/custom_printf/default.nix
rename to pkgs/development/ocaml-modules/custom-printf/default.nix
index 05a8ecfe616b..f435e53314a9 100644
--- a/pkgs/development/ocaml-modules/custom_printf/default.nix
+++ b/pkgs/development/ocaml-modules/custom-printf/default.nix
@@ -1,7 +1,7 @@
-{stdenv, buildOcaml, fetchurl, type_conv, sexplib, pa_ounit}:
+{stdenv, buildOcaml, fetchurl, type-conv, sexplib, pa-ounit}:
 
 buildOcaml rec {
-  name = "custom_printf";
+  name = "custom-printf";
   version = "112.24.00";
 
   minimumSupportedOcamlVersion = "4.02";
@@ -11,8 +11,8 @@ buildOcaml rec {
     sha256 = "dad3aface92c53e8fbcc12cc9358c4767cb1cb09857d4819a10ed98eccaca8f9";
   };
 
-  buildInputs = [ pa_ounit ];
-  propagatedBuildInputs = [ type_conv sexplib ];
+  buildInputs = [ pa-ounit ];
+  propagatedBuildInputs = [ type-conv sexplib ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/custom_printf;
diff --git a/pkgs/development/ocaml-modules/enumerate/default.nix b/pkgs/development/ocaml-modules/enumerate/default.nix
index ce20cdd47bb4..f0f80eb2ecd4 100644
--- a/pkgs/development/ocaml-modules/enumerate/default.nix
+++ b/pkgs/development/ocaml-modules/enumerate/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, ocaml, findlib, type_conv, camlp4 }:
+{ stdenv, fetchurl, ocaml, findlib, type-conv, camlp4 }:
 
 assert stdenv.lib.versionAtLeast (stdenv.lib.getVersion ocaml) "4.00";
 
@@ -11,7 +11,7 @@ stdenv.mkDerivation {
   };
 
   buildInputs = [ ocaml findlib ];
-  propagatedBuildInputs = [ type_conv camlp4 ];
+  propagatedBuildInputs = [ type-conv camlp4 ];
 
   createFindlibDestdir = true;
 
diff --git a/pkgs/development/ocaml-modules/erm_xml/default.nix b/pkgs/development/ocaml-modules/erm-xml/default.nix
similarity index 93%
rename from pkgs/development/ocaml-modules/erm_xml/default.nix
rename to pkgs/development/ocaml-modules/erm-xml/default.nix
index 0ff2a725ea2b..c60ef70ef698 100644
--- a/pkgs/development/ocaml-modules/erm_xml/default.nix
+++ b/pkgs/development/ocaml-modules/erm-xml/default.nix
@@ -3,7 +3,7 @@
 let version = "0.3"; in
 
 stdenv.mkDerivation {
-  name = "ocaml-erm_xml-${version}";
+  name = "ocaml-erm-xml-${version}";
 
   src = fetchzip {
     url = "https://github.com/ermine/xml/archive/v${version}.tar.gz";
diff --git a/pkgs/development/ocaml-modules/erm_xmpp/default.nix b/pkgs/development/ocaml-modules/erm-xmpp/default.nix
similarity index 84%
rename from pkgs/development/ocaml-modules/erm_xmpp/default.nix
rename to pkgs/development/ocaml-modules/erm-xmpp/default.nix
index 7508a14738dc..35b090510465 100644
--- a/pkgs/development/ocaml-modules/erm_xmpp/default.nix
+++ b/pkgs/development/ocaml-modules/erm-xmpp/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, fetchzip, ocaml, findlib, erm_xml, cryptokit, camlp4 }:
+{ stdenv, fetchurl, fetchzip, ocaml, findlib, erm-xml, cryptokit, camlp4 }:
 
 let
   version = "0.2";
@@ -9,7 +9,7 @@ let
 in
 
 stdenv.mkDerivation {
-  name = "ocaml-erm_xmpp-${version}";
+  name = "ocaml-erm-xmpp-${version}";
 
   src = fetchzip {
     url = "https://github.com/ermine/xmpp/archive/v${version}.tar.gz";
@@ -19,7 +19,7 @@ stdenv.mkDerivation {
   patches = [ disable-tests ];
 
   buildInputs = [ ocaml findlib camlp4 ];
-  propagatedBuildInputs = [ erm_xml cryptokit ];
+  propagatedBuildInputs = [ erm-xml cryptokit ];
 
   createFindlibDestdir = true;
 
diff --git a/pkgs/development/ocaml-modules/fieldslib/default.nix b/pkgs/development/ocaml-modules/fieldslib/default.nix
index 385487903290..cb73f56fbd83 100644
--- a/pkgs/development/ocaml-modules/fieldslib/default.nix
+++ b/pkgs/development/ocaml-modules/fieldslib/default.nix
@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, ocaml, findlib, type_conv, camlp4 }:
+{ stdenv, fetchurl, ocaml, findlib, type-conv, camlp4 }:
 
 assert stdenv.lib.versionOlder "4.00" (stdenv.lib.getVersion ocaml);
 
@@ -11,7 +11,7 @@ stdenv.mkDerivation {
   };
 
   buildInputs = [ ocaml findlib ];
-  propagatedBuildInputs = [ type_conv camlp4 ];
+  propagatedBuildInputs = [ type-conv camlp4 ];
 
   createFindlibDestdir = true;
 
diff --git a/pkgs/development/ocaml-modules/odn/default.nix b/pkgs/development/ocaml-modules/odn/default.nix
index eaeb7e7b22f7..c7d4aa52c474 100644
--- a/pkgs/development/ocaml-modules/odn/default.nix
+++ b/pkgs/development/ocaml-modules/odn/default.nix
@@ -1,4 +1,4 @@
-{stdenv, fetchurl, ocaml, findlib, type_conv, ounit, camlp4}:
+{stdenv, fetchurl, ocaml, findlib, type-conv, ounit, camlp4}:
 
 stdenv.mkDerivation {
   name = "ocaml-data-notation-0.0.11";
@@ -8,7 +8,7 @@ stdenv.mkDerivation {
     sha256 = "09a8zdyifpc2nl4hdvg9206142y31cq95ajgij011s1qcg3z93lj";
   };
 
-  buildInputs = [ocaml findlib type_conv ounit camlp4];
+  buildInputs = [ocaml findlib type-conv ounit camlp4];
 
   createFindlibDestdir = true;
 
diff --git a/pkgs/development/ocaml-modules/pa_bench/default.nix b/pkgs/development/ocaml-modules/pa-bench/default.nix
similarity index 77%
rename from pkgs/development/ocaml-modules/pa_bench/default.nix
rename to pkgs/development/ocaml-modules/pa-bench/default.nix
index d8ce0dbc7eac..926a61fff66f 100644
--- a/pkgs/development/ocaml-modules/pa_bench/default.nix
+++ b/pkgs/development/ocaml-modules/pa-bench/default.nix
@@ -1,7 +1,7 @@
-{stdenv, buildOcaml, fetchurl, type_conv, pa_ounit}:
+{stdenv, buildOcaml, fetchurl, type-conv, pa-ounit}:
 
 buildOcaml rec {
-  name = "pa_bench";
+  name = "pa-bench";
   version = "112.06.00";
 
   minimumSupportedOcamlVersion = "4.00";
@@ -11,8 +11,8 @@ buildOcaml rec {
     sha256 = "e3401e37f1d3d4acb957fd46a192d0ffcefeb0bedee63bbeb26969af1d540870";
   };
 
-  buildInputs = [ pa_ounit ];
-  propagatedBuildInputs = [ type_conv ];
+  buildInputs = [ pa-ounit ];
+  propagatedBuildInputs = [ type-conv ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/pa_bench;
diff --git a/pkgs/development/ocaml-modules/pa_ounit/default.nix b/pkgs/development/ocaml-modules/pa-ounit/default.nix
similarity index 96%
rename from pkgs/development/ocaml-modules/pa_ounit/default.nix
rename to pkgs/development/ocaml-modules/pa-ounit/default.nix
index 5970aba1e502..05a38c814a09 100644
--- a/pkgs/development/ocaml-modules/pa_ounit/default.nix
+++ b/pkgs/development/ocaml-modules/pa-ounit/default.nix
@@ -1,7 +1,7 @@
 {stdenv, buildOcaml, fetchurl, ounit}:
 
 buildOcaml rec {
-  name = "pa_ounit";
+  name = "pa-ounit";
   version = "112.24.00";
 
   src = fetchurl {
diff --git a/pkgs/development/ocaml-modules/pa_test/default.nix b/pkgs/development/ocaml-modules/pa-test/default.nix
similarity index 74%
rename from pkgs/development/ocaml-modules/pa_test/default.nix
rename to pkgs/development/ocaml-modules/pa-test/default.nix
index faf17e20dc1e..81b5854348bc 100644
--- a/pkgs/development/ocaml-modules/pa_test/default.nix
+++ b/pkgs/development/ocaml-modules/pa-test/default.nix
@@ -1,7 +1,7 @@
-{stdenv, buildOcaml, fetchurl, type_conv, pa_ounit, sexplib, herelib}:
+{stdenv, buildOcaml, fetchurl, type-conv, pa-ounit, sexplib, herelib}:
 
 buildOcaml rec {
-  name = "pa_test";
+  name = "pa-test";
   version = "112.24.00";
 
   minimumSupportedOcamlVersion = "4.00";
@@ -11,8 +11,8 @@ buildOcaml rec {
     sha256 = "b03d13c2bc9fa9a4b1c507d7108d965202160f83e9781d430d3b53a1993e30d6";
   };
 
-  buildInputs = [ pa_ounit ];
-  propagatedBuildInputs = [ type_conv sexplib herelib ];
+  buildInputs = [ pa-ounit ];
+  propagatedBuildInputs = [ type-conv sexplib herelib ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/pa_test;
diff --git a/pkgs/development/ocaml-modules/re2/default.nix b/pkgs/development/ocaml-modules/re2/default.nix
index e89e28fe1e55..31922d2aab8f 100644
--- a/pkgs/development/ocaml-modules/re2/default.nix
+++ b/pkgs/development/ocaml-modules/re2/default.nix
@@ -1,5 +1,5 @@
-{stdenv, buildOcaml, fetchurl, ocaml, core, pa_ounit, pa_test,
- bin_prot, comparelib, sexplib, rsync}:
+{stdenv, buildOcaml, fetchurl, ocaml, core, pa-ounit, pa-test,
+ bin-prot, comparelib, sexplib, rsync}:
 
 buildOcaml rec {
   name = "re2";
@@ -15,8 +15,8 @@ buildOcaml rec {
             then [./Makefile.patch ./myocamlbuild.patch]
             else null;
 
-  buildInputs = [ pa_ounit pa_test rsync ];
-  propagatedBuildInputs = [ core bin_prot comparelib sexplib ];
+  buildInputs = [ pa-ounit pa-test rsync ];
+  propagatedBuildInputs = [ core bin-prot comparelib sexplib ];
 
   hasSharedObjects = true;
 
diff --git a/pkgs/development/ocaml-modules/sexplib/108.08.00.nix b/pkgs/development/ocaml-modules/sexplib/108.08.00.nix
index dd9e89bcef70..0067d68e1294 100644
--- a/pkgs/development/ocaml-modules/sexplib/108.08.00.nix
+++ b/pkgs/development/ocaml-modules/sexplib/108.08.00.nix
@@ -1,4 +1,4 @@
-{stdenv, fetchurl, ocaml, findlib, type_conv, camlp4}:
+{stdenv, fetchurl, ocaml, findlib, type-conv, camlp4}:
 
 let
   ocaml_version = (builtins.parseDrvName ocaml.name).version;
@@ -15,7 +15,7 @@ stdenv.mkDerivation {
   };
 
   buildInputs = [ocaml findlib];
-  propagatedBuildInputs = [type_conv camlp4];
+  propagatedBuildInputs = [type-conv camlp4];
 
   createFindlibDestdir = true;
 
diff --git a/pkgs/development/ocaml-modules/sexplib/111.25.00.nix b/pkgs/development/ocaml-modules/sexplib/111.25.00.nix
index 61d46e205fa6..0a817728393a 100644
--- a/pkgs/development/ocaml-modules/sexplib/111.25.00.nix
+++ b/pkgs/development/ocaml-modules/sexplib/111.25.00.nix
@@ -1,4 +1,4 @@
-{stdenv, fetchurl, ocaml, findlib, type_conv, camlp4}:
+{stdenv, fetchurl, ocaml, findlib, type-conv, camlp4}:
 
 let
   ocaml_version = (builtins.parseDrvName ocaml.name).version;
@@ -15,7 +15,7 @@ stdenv.mkDerivation {
   };
 
   buildInputs = [ocaml findlib];
-  propagatedBuildInputs = [type_conv camlp4];
+  propagatedBuildInputs = [type-conv camlp4];
 
   createFindlibDestdir = true;
 
diff --git a/pkgs/development/ocaml-modules/sexplib/112.24.01.nix b/pkgs/development/ocaml-modules/sexplib/112.24.01.nix
index b63b5af05e82..31ef738b3a20 100644
--- a/pkgs/development/ocaml-modules/sexplib/112.24.01.nix
+++ b/pkgs/development/ocaml-modules/sexplib/112.24.01.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, type_conv, camlp4}:
+{stdenv, buildOcaml, fetchurl, type-conv, camlp4}:
 
 buildOcaml rec {
   minimumSupportedOcamlVersion = "4.02";
@@ -10,7 +10,7 @@ buildOcaml rec {
     sha256 = "5f776aee295cc51c952aecd4b74b52dd2b850c665cc25b3d69bc42014d3ba073";
   };
 
-  propagatedBuildInputs = [ type_conv camlp4 ];
+  propagatedBuildInputs = [ type-conv camlp4 ];
 
   meta = with stdenv.lib; {
     homepage = https://ocaml.janestreet.com/;
diff --git a/pkgs/development/ocaml-modules/textutils/default.nix b/pkgs/development/ocaml-modules/textutils/default.nix
index 377b94eff8b8..07a79519745a 100644
--- a/pkgs/development/ocaml-modules/textutils/default.nix
+++ b/pkgs/development/ocaml-modules/textutils/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, core, pa_ounit, pa_test, sexplib}:
+{stdenv, buildOcaml, fetchurl, core, pa-ounit, pa-test, sexplib}:
 
 buildOcaml rec {
   name = "textutils";
@@ -11,8 +11,8 @@ buildOcaml rec {
     sha256 = "605d9fde66dc2d777721c936aa521e17169c143efaf9ff29619a7f273a7d0052";
   };
 
-  buildInputs = [ pa_test ];
-  propagatedBuildInputs = [ core pa_ounit sexplib ];
+  buildInputs = [ pa-test ];
+  propagatedBuildInputs = [ core pa-ounit sexplib ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/textutils;
diff --git a/pkgs/development/ocaml-modules/type_conv/108.08.00.nix b/pkgs/development/ocaml-modules/type-conv/108.08.00.nix
similarity index 95%
rename from pkgs/development/ocaml-modules/type_conv/108.08.00.nix
rename to pkgs/development/ocaml-modules/type-conv/108.08.00.nix
index d3e32105f7df..281ef90d42db 100644
--- a/pkgs/development/ocaml-modules/type_conv/108.08.00.nix
+++ b/pkgs/development/ocaml-modules/type-conv/108.08.00.nix
@@ -7,7 +7,7 @@ in
 assert stdenv.lib.versionOlder "3.12" ocaml_version;
 
 stdenv.mkDerivation {
-  name = "ocaml-type_conv-108.08.00";
+  name = "ocaml-type-conv-108.08.00";
 
   src = fetchurl {
     url = https://ocaml.janestreet.com/ocaml-core/108.08.00/individual/type_conv-108.08.00.tar.gz;
diff --git a/pkgs/development/ocaml-modules/type_conv/109.60.01.nix b/pkgs/development/ocaml-modules/type-conv/109.60.01.nix
similarity index 95%
rename from pkgs/development/ocaml-modules/type_conv/109.60.01.nix
rename to pkgs/development/ocaml-modules/type-conv/109.60.01.nix
index fe42dd5ddcbd..91f6b32cb0a1 100644
--- a/pkgs/development/ocaml-modules/type_conv/109.60.01.nix
+++ b/pkgs/development/ocaml-modules/type-conv/109.60.01.nix
@@ -7,7 +7,7 @@ in
 assert stdenv.lib.versionOlder "4.00" ocaml_version;
 
 stdenv.mkDerivation {
-  name = "ocaml-type_conv-109.60.01";
+  name = "ocaml-type-conv-109.60.01";
 
   src = fetchurl {
     url = https://github.com/janestreet/type_conv/archive/109.60.01.tar.gz;
diff --git a/pkgs/development/ocaml-modules/type_conv/112.01.01.nix b/pkgs/development/ocaml-modules/type-conv/112.01.01.nix
similarity index 96%
rename from pkgs/development/ocaml-modules/type_conv/112.01.01.nix
rename to pkgs/development/ocaml-modules/type-conv/112.01.01.nix
index e65306d15018..d6e0cea6eaa5 100644
--- a/pkgs/development/ocaml-modules/type_conv/112.01.01.nix
+++ b/pkgs/development/ocaml-modules/type-conv/112.01.01.nix
@@ -3,7 +3,7 @@
 buildOcaml rec {
   minimumSupportedOcamlVersion = "4.02";
 
-  name = "type_conv";
+  name = "type-conv";
   version = "112.01.01";
 
   src = fetchurl {
diff --git a/pkgs/development/ocaml-modules/typerep/default.nix b/pkgs/development/ocaml-modules/typerep/default.nix
index 9500579e2458..168b61085edb 100644
--- a/pkgs/development/ocaml-modules/typerep/default.nix
+++ b/pkgs/development/ocaml-modules/typerep/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, type_conv}:
+{stdenv, buildOcaml, fetchurl, type-conv}:
 
 buildOcaml rec {
   name = "typerep";
@@ -11,7 +11,7 @@ buildOcaml rec {
     sha256 = "4f1ab611a00aaf774e9774b26b687233e0c70d91f684415a876f094a9969eada";
   };
 
-  propagatedBuildInputs = [ type_conv ];
+  propagatedBuildInputs = [ type-conv ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/typerep;
diff --git a/pkgs/development/ocaml-modules/variantslib/default.nix b/pkgs/development/ocaml-modules/variantslib/default.nix
index cb25b844606d..f8e60205e4f1 100644
--- a/pkgs/development/ocaml-modules/variantslib/default.nix
+++ b/pkgs/development/ocaml-modules/variantslib/default.nix
@@ -1,4 +1,4 @@
-{stdenv, buildOcaml, fetchurl, type_conv}:
+{stdenv, buildOcaml, fetchurl, type-conv}:
 
 buildOcaml rec {
   name = "variantslib";
@@ -11,7 +11,7 @@ buildOcaml rec {
     sha256 = "a948dcdd4ca54786fe0646386b6e37a9db03bf276c6557ea374d82740bf18055";
   };
 
-  propagatedBuildInputs = [ type_conv ];
+  propagatedBuildInputs = [ type-conv ];
 
   meta = with stdenv.lib; {
     homepage = https://github.com/janestreet/variantslib;
diff --git a/pkgs/development/tools/ocaml/oasis/default.nix b/pkgs/development/tools/ocaml/oasis/default.nix
index e823466f4174..da94fed0831e 100644
--- a/pkgs/development/tools/ocaml/oasis/default.nix
+++ b/pkgs/development/tools/ocaml/oasis/default.nix
@@ -1,4 +1,4 @@
-{stdenv, fetchurl, ocaml, findlib, ocaml_data_notation, type_conv, camlp4,
+{stdenv, fetchurl, ocaml, findlib, ocaml-data-notation, type-conv, camlp4,
  ocamlmod, ocamlify, ounit, expect}:
 
 stdenv.mkDerivation {
@@ -13,10 +13,10 @@ stdenv.mkDerivation {
 
   buildInputs =
     [
-      ocaml findlib type_conv ocamlmod ocamlify ounit camlp4
+      ocaml findlib type-conv ocamlmod ocamlify ounit camlp4
     ];
 
-  propagatedBuildInputs = [ ocaml_data_notation ];
+  propagatedBuildInputs = [ ocaml-data-notation ];
 
   configurePhase = "ocaml setup.ml -configure --prefix $out";
   buildPhase     = "ocaml setup.ml -build";
diff --git a/pkgs/tools/typesetting/patoline/default.nix b/pkgs/tools/typesetting/patoline/default.nix
index a39105c83145..9da588b934dc 100644
--- a/pkgs/tools/typesetting/patoline/default.nix
+++ b/pkgs/tools/typesetting/patoline/default.nix
@@ -2,7 +2,7 @@
 { stdenv, fetchurl, ncurses, mesa, freeglut, libzip, 
    ocaml, findlib, camomile, 
    dypgen, ocaml_sqlite3, camlzip, 
-   lablgtk, camlimages, ocaml_cairo,
+   lablgtk, camlimages, ocaml-cairo,
    lablgl, ocamlnet, cryptokit,
    ocaml_pcre }:
 
@@ -21,13 +21,13 @@ stdenv.mkDerivation {
   createFindlibDestdir = true;
    
    buildInputs = [ ocaml findlib dypgen camomile ocaml_sqlite3 camlzip 
-   lablgtk camlimages ocaml_cairo
+   lablgtk camlimages ocaml-cairo
    lablgl ocamlnet cryptokit
    ocaml_pcre ncurses mesa freeglut libzip ];
 
   propagatedbuildInputs = [ camomile 
    dypgen ocaml_sqlite3 camlzip 
-   lablgtk camlimages ocaml_cairo
+   lablgtk camlimages ocaml-cairo
    lablgl ocamlnet cryptokit
    ocaml_pcre ncurses mesa freeglut libzip ];
 
diff --git a/pkgs/top-level/all-packages.nix b/pkgs/top-level/all-packages.nix
index 7c0b9208e7c9..2c6d1f75a963 100644
--- a/pkgs/top-level/all-packages.nix
+++ b/pkgs/top-level/all-packages.nix
@@ -4310,17 +4310,17 @@ let
 
     asn1-combinators = callPackage ../development/ocaml-modules/asn1-combinators { };
 
-    async_extra = callPackage ../development/ocaml-modules/async_extra { };
+    async-extra = callPackage ../development/ocaml-modules/async-extra { };
 
-    async_find = callPackage ../development/ocaml-modules/async_find { };
+    async-find = callPackage ../development/ocaml-modules/async-find { };
 
-    async_kernel = callPackage ../development/ocaml-modules/async_kernel { };
+    async-kernel = callPackage ../development/ocaml-modules/async-kernel { };
 
-    async_shell = callPackage ../development/ocaml-modules/async_shell { };
+    async-shell = callPackage ../development/ocaml-modules/async-shell { };
 
-    async_ssl = callPackage ../development/ocaml-modules/async_ssl { };
+    async-ssl = callPackage ../development/ocaml-modules/async-ssl { };
 
-    async_unix = callPackage ../development/ocaml-modules/async_unix { };
+    async-unix = callPackage ../development/ocaml-modules/async-unix { };
 
     async =
       if lib.versionOlder "4.02" ocaml_version
@@ -4396,11 +4396,11 @@ let
 
     biniou = callPackage ../development/ocaml-modules/biniou { };
 
-    bin_prot = callPackage ../development/ocaml-modules/bin_prot { };
+    bin-prot = callPackage ../development/ocaml-modules/bin-prot { };
 
-    ocaml_cairo = callPackage ../development/ocaml-modules/ocaml-cairo { };
+    ocaml-cairo = callPackage ../development/ocaml-modules/ocaml-cairo { };
 
-    ocaml_cairo2 = callPackage ../development/ocaml-modules/ocaml-cairo2 { };
+    ocaml-cairo2 = callPackage ../development/ocaml-modules/ocaml-cairo2 { };
 
     cil = callPackage ../development/ocaml-modules/cil { };
 
@@ -4424,7 +4424,7 @@ let
 
     csv = callPackage ../development/ocaml-modules/csv { };
 
-    custom_printf = callPackage ../development/ocaml-modules/custom_printf { };
+    custom-printf = callPackage ../development/ocaml-modules/custom-printf { };
 
     ctypes = callPackage ../development/ocaml-modules/ctypes { };
 
@@ -4440,9 +4440,9 @@ let
 
     enumerate = callPackage ../development/ocaml-modules/enumerate { };
 
-    erm_xml = callPackage ../development/ocaml-modules/erm_xml { };
+    erm-xml = callPackage ../development/ocaml-modules/erm-xml { };
 
-    erm_xmpp = callPackage ../development/ocaml-modules/erm_xmpp { };
+    erm-xmpp = callPackage ../development/ocaml-modules/erm-xmpp { };
 
     ezjsonm = callPackage ../development/ocaml-modules/ezjsonm {
       lwt = ocaml_lwt;
@@ -4535,15 +4535,15 @@ let
 
     comparelib = callPackage ../development/ocaml-modules/comparelib { };
 
-    core_extended = callPackage ../development/ocaml-modules/core_extended { };
+    core-extended = callPackage ../development/ocaml-modules/core-extended { };
 
-    core_kernel = callPackage ../development/ocaml-modules/core_kernel { };
+    core-kernel = callPackage ../development/ocaml-modules/core-kernel { };
 
     core = callPackage ../development/ocaml-modules/core { };
 
-    ocaml_cryptgps = callPackage ../development/ocaml-modules/cryptgps { };
+    ocaml-cryptgps = callPackage ../development/ocaml-modules/cryptgps { };
 
-    ocaml_data_notation = callPackage ../development/ocaml-modules/odn { };
+    ocaml-data-notation = callPackage ../development/ocaml-modules/odn { };
 
     ocaml_expat = callPackage ../development/ocaml-modules/expat { };
 
@@ -4617,16 +4617,16 @@ let
 
     textutils = callPackage ../development/ocaml-modules/textutils { };
 
-    type_conv_108_08_00 = callPackage ../development/ocaml-modules/type_conv/108.08.00.nix { };
-    type_conv_109_60_01 = callPackage ../development/ocaml-modules/type_conv/109.60.01.nix { };
-    type_conv_112_01_01 = callPackage ../development/ocaml-modules/type_conv/112.01.01.nix { };
-    type_conv =
+    type-conv-108_08_00 = callPackage ../development/ocaml-modules/type-conv/108.08.00.nix { };
+    type-conv-109_60_01 = callPackage ../development/ocaml-modules/type-conv/109.60.01.nix { };
+    type-conv-112_01_01 = callPackage ../development/ocaml-modules/type-conv/112.01.01.nix { };
+    type-conv =
       if lib.versionOlder "4.02" ocaml_version
-      then type_conv_112_01_01
+      then type-conv-112_01_01
       else if lib.versionOlder "4.00" ocaml_version
-      then type_conv_109_60_01
+      then type-conv-109_60_01
       else if lib.versionOlder "3.12" ocaml_version
-      then type_conv_108_08_00
+      then type-conv-108_08_00
       else null;
 
     sexplib_108_08_00 = callPackage ../development/ocaml-modules/sexplib/108.08.00.nix { };
@@ -4649,11 +4649,11 @@ let
 
     ocurl = callPackage ../development/ocaml-modules/ocurl { };
 
-    pa_ounit = callPackage ../development/ocaml-modules/pa_ounit { };
+    pa-ounit = callPackage ../development/ocaml-modules/pa-ounit { };
 
-    pa_bench = callPackage ../development/ocaml-modules/pa_bench { };
+    pa-bench = callPackage ../development/ocaml-modules/pa-bench { };
 
-    pa_test = callPackage ../development/ocaml-modules/pa_test { };
+    pa-test = callPackage ../development/ocaml-modules/pa-test { };
 
     pipebang = callPackage ../development/ocaml-modules/pipebang { };
 
@@ -4714,6 +4714,32 @@ let
       oasis = ocaml_oasis;
     };
 
+
+    # Attributes for backward compatibility.
+    async_extra = async-extra; # added 2015-07-21
+    async_find = async-find; # added 2015-07-21
+    async_kernel = async-kernel; # added 2015-07-21
+    async_shell = async-shell; # added 2015-07-21
+    async_ssl = async-ssl; # added 2015-07-21
+    async_unix = async-unix; # added 2015-07-21
+    bin_prot = bin-prot; # added 2015-07-21
+    core_extended = core-extended; # added 2015-07-21
+    core_kernel = core-kernel; # added 2015-07-21
+    custom_printf = custom-printf; # added 2015-07-21
+    erm_xml = erm-xml; # added 2015-07-21
+    erm_xmpp = erm-xmpp; # added 2015-07-21
+    ocaml_cairo = ocaml-cairo; # added 2015-07-21
+    ocaml_cairo2 = ocaml-cairo2; # added 2015-07-21
+    ocaml_cryptgps = ocaml-cryptgps; # added 2015-07-21
+    ocaml_data_notation = ocaml-data-notation; # added 2015-07-21
+    pa_bench = pa-bench; # added 2015-07-21
+    pa_ounit = pa-ounit; # added 2015-07-21
+    pa_test = pa-test; # added 2015-07-21
+    type_conv_108_08_00 = type-conv-108_08_00; # added 2015-07-21
+    type_conv_109_60_01 = type-conv-109_60_01; # added 2015-07-21
+    type_conv_112_01_01 = type-conv-112_01_01; # added 2015-07-21
+    type_conv = type-conv; # added 2015-07-21
+
   };
 
   ocamlPackages = recurseIntoAttrs ocamlPackages_4_01_0;
@@ -15255,7 +15281,7 @@ let
       buildInputs = [ stdenv ncurses mesa freeglut libzip gcc
                                    pack.ocaml pack.findlib pack.camomile
                                    pack.dypgen pack.ocaml_sqlite3 pack.camlzip
-                                   pack.lablgtk pack.camlimages pack.ocaml_cairo
+                                   pack.lablgtk pack.camlimages pack.ocaml-cairo
                                    pack.lablgl pack.ocamlnet pack.cryptokit
                                    pack.ocaml_pcre pack.patoline
                                    ];