diff --git a/pkgs/python-packages.nix b/pkgs/python-packages.nix
--- a/pkgs/python-packages.nix
+++ b/pkgs/python-packages.nix
@@ -90,13 +90,13 @@
     };
   };
   dulwich = super.buildPythonPackage {
-    name = "dulwich-0.12.0";
+    name = "dulwich-0.13.0";
     buildInputs = with self; [];
     doCheck = false;
     propagatedBuildInputs = with self; [];
     src = fetchurl {
-      url = "https://pypi.python.org/packages/6f/04/fbe561b6d45c0ec758330d5b7f5ba4b6cb4f1ca1ab49859d2fc16320da75/dulwich-0.12.0.tar.gz";
-      md5 = "f3a8a12bd9f9dd8c233e18f3d49436fa";
+      url = "https://pypi.python.org/packages/84/95/732d280eee829dacc954e8109f97b47abcadcca472c2ab013e1635eb4792/dulwich-0.13.0.tar.gz";
+      md5 = "6dede0626657c2bd08f48ca1221eea91";
     };
   };
   greenlet = super.buildPythonPackage {
diff --git a/requirements.txt b/requirements.txt
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,6 +1,6 @@
 Beaker==1.7.0
 configobj==5.0.6
-dulwich==0.12.0
+dulwich==0.13.0
 hgsubversion==1.8.6
 infrae.cache==1.0.1
 mercurial==3.8.3