diff --git a/pkgs/development/ocaml-modules/piqi/default.nix b/pkgs/development/ocaml-modules/piqi/default.nix
index c492035f4f9..f3c489723b2 100644
--- a/pkgs/development/ocaml-modules/piqi/default.nix
+++ b/pkgs/development/ocaml-modules/piqi/default.nix
@@ -1,16 +1,19 @@
-{ stdenv, fetchurl, ocaml, findlib, which, ulex, easy-format, ocaml_optcomp, xmlm, base64 }:
+{ stdenv, fetchFromGitHub, ocaml, findlib, which, sedlex_2, easy-format, xmlm, base64 }:
 
 stdenv.mkDerivation rec {
-  version = "0.6.14";
+  version = "0.6.15";
   pname = "piqi";
+  name = "ocaml${ocaml.version}-${pname}-${version}";
  
-  src = fetchurl {
-    url = "https://github.com/alavrik/piqi/archive/v${version}.tar.gz";
-    sha256 = "1ssccnwqzfyf7syfq2fv4zyhwayxwd75rhq9y28mvq1w6qbww4l7";
+  src = fetchFromGitHub {
+    owner = "alavrik";
+    repo = pname;
+    rev = "v${version}";
+    sha256 = "0v04hs85xv6d4ysqxyv1dik34dx49yab9shpi4x7iv19qlzl7csb";
   };
 
-  buildInputs = [ ocaml findlib which ocaml_optcomp ];
-  propagatedBuildInputs = [ulex xmlm easy-format base64];
+  buildInputs = [ ocaml findlib which ];
+  propagatedBuildInputs = [ sedlex_2 xmlm easy-format base64 ];
 
   patches = [ ./no-ocamlpath-override.patch ];
 
diff --git a/pkgs/top-level/ocaml-packages.nix b/pkgs/top-level/ocaml-packages.nix
index 4be489c76eb..5ee24287dd6 100644
--- a/pkgs/top-level/ocaml-packages.nix
+++ b/pkgs/top-level/ocaml-packages.nix
@@ -712,9 +712,7 @@ let
 
     phylogenetics = callPackage ../development/ocaml-modules/phylogenetics { };
 
-    piqi = callPackage ../development/ocaml-modules/piqi {
-      base64 = base64_2;
-    };
+    piqi = callPackage ../development/ocaml-modules/piqi { };
 
     piqi-ocaml = callPackage ../development/ocaml-modules/piqi-ocaml { };