diff --git a/pkgs/development/libraries/zeitgeist/default.nix b/pkgs/development/libraries/zeitgeist/default.nix
index 3ef43baca5ed..d0de624890b5 100644
--- a/pkgs/development/libraries/zeitgeist/default.nix
+++ b/pkgs/development/libraries/zeitgeist/default.nix
@@ -3,10 +3,11 @@
 , gtk3, json_glib, librdf_raptor2, pythonPackages, dbus_glib }:
 
 stdenv.mkDerivation rec {
-  name = "zeitgeist-0.0.14";
+  version = "0.9.15";
+  name = "zeitgeist-${version}";
 
   src = fetchurl {
-    url = "https://github.com/seiflotfy/zeitgeist/archive/v0.9.15.tar.gz";
+    url = "https://github.com/seiflotfy/zeitgeist/archive/v${version}.tar.gz";
     sha256 = "07pnc7kmjpd0ncm32z6s3ny5p4zl52v9lld0n0f8sp6cw87k12p0";
   };
 
diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index a44401e664dd..75785ebc8a55 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -7067,12 +7067,28 @@ rec {
 
     # error: invalid command 'test'
     doCheck = false;
+    
+    propagatedBuildInputs = [ isodate ];
 
     meta = {
       description = "RDFLib is a Python library for working with RDF, a simple yet powerful language for representing information.";
       homepage = http://www.rdflib.net/;
     };
   });
+  
+  isodate = buildPythonPackage rec {
+    name = "isodate-0.5.0";
+
+    src = fetchurl {
+      url = "https://pypi.python.org/packages/source/i/isodate/${name}.tar.gz";
+      md5 = "9a267e9327feb3d021cae26002ba6e0e";
+    };
+
+    meta = with stdenv.lib; {
+      description = "ISO 8601 date/time parser";
+      homepage = http://cheeseshop.python.org/pypi/isodate;
+    };
+  };
 
 
   robotframework = buildPythonPackage rec {