diff --git a/pkgs/development/interpreters/php/5.3.nix b/pkgs/development/interpreters/php/5.3.nix
index ff136329d607..7d51a74020fb 100644
--- a/pkgs/development/interpreters/php/5.3.nix
+++ b/pkgs/development/interpreters/php/5.3.nix
@@ -1,7 +1,11 @@
 { stdenv, fetchurl, composableDerivation, autoconf, automake, flex, bison
 , apacheHttpd, mysql, libxml2, readline, zlib, curl, gd, postgresql, gettext
 , openssl, pkgconfig, sqlite, config, libiconv, libjpeg, libpng, freetype
-, libxslt }:
+, libxslt, libmcrypt }:
+
+let
+  libmcryptOverride = libmcrypt.override { disablePosixThreads = true; };
+in
 
 composableDerivation.composableDerivation {} ( fixed : let inherit (fixed.fixed) version; in {
 
@@ -116,6 +120,11 @@ composableDerivation.composableDerivation {} ( fixed : let inherit (fixed.fixed)
         buildInputs = [libxslt];
       };
 
+      mcrypt = {
+        configureFlags = ["--with-mcrypt=${libmcrypt}"];
+        buildInputs = [libmcryptOverride];
+      };
+
       /*
          php is build within this derivation in order to add the xdebug lines to the php.ini.
          So both Apache and command line php both use xdebug without having to configure anything.
@@ -148,6 +157,7 @@ composableDerivation.composableDerivation {} ( fixed : let inherit (fixed.fixed)
     mbstringSupport = config.php.mbstring or true;
     gdSupport = config.php.gd or true;
     xslSupport = config.php.xsl or false;
+    mcryptSupport = config.php.mcrypt or false;
   };
 
   configurePhase = ''
diff --git a/pkgs/development/libraries/libmcrypt/default.nix b/pkgs/development/libraries/libmcrypt/default.nix
index eac577869e29..79019cbc4891 100644
--- a/pkgs/development/libraries/libmcrypt/default.nix
+++ b/pkgs/development/libraries/libmcrypt/default.nix
@@ -1,4 +1,6 @@
-{ stdenv, fetchurl }:
+{ stdenv, fetchurl, disablePosixThreads ? false }:
+
+with stdenv.lib;
 
 stdenv.mkDerivation rec {
   name = "libmcrypt-2.5.8";
@@ -10,7 +12,12 @@ stdenv.mkDerivation rec {
 
   buildInputs = [];
 
+  configureFlags = optional disablePosixThreads
+    [ "--disable-posix-threads" ];
+
   meta = {
+    description = "MCrypt is a replacement for the old crypt() package and crypt(1) command, with extensions.";
     homepage = http://mcrypt.sourceforge.net;
+    license = "GPL";
   };
 }