diff --git a/pkgs/development/libraries/librdf/redland.nix b/pkgs/development/libraries/librdf/redland.nix
index 766b4aa341f..633611273a3 100644
--- a/pkgs/development/libraries/librdf/redland.nix
+++ b/pkgs/development/libraries/librdf/redland.nix
@@ -1,5 +1,5 @@
 { stdenv, fetchurl, pkgconfig, openssl, libxslt, perl
-, curl, pcre, libxml2, librdf_rasqal
+, curl, pcre, libxml2, librdf_rasqal, gmp
 , mysql, withMysql ? false
 , postgresql, withPostgresql ? false
 , sqlite, withSqlite ? true
@@ -16,7 +16,7 @@ stdenv.mkDerivation rec {
 
   nativeBuildInputs = [ perl pkgconfig ];
 
-  buildInputs = [ openssl libxslt curl pcre libxml2 ]
+  buildInputs = [ openssl libxslt curl pcre libxml2 gmp ]
     ++ stdenv.lib.optional withMysql mysql.connector-c
     ++ stdenv.lib.optional withSqlite sqlite
     ++ stdenv.lib.optional withPostgresql postgresql
@@ -38,6 +38,6 @@ stdenv.mkDerivation rec {
 
   meta = {
     homepage = http://librdf.org/;
-    platforms = stdenv.lib.platforms.linux;
+    platforms = stdenv.lib.platforms.unix;
   };
 }