diff --git a/pkgs/top-level/python-packages.nix b/pkgs/top-level/python-packages.nix
index d4e565ddfdf..c29c0268b00 100644
--- a/pkgs/top-level/python-packages.nix
+++ b/pkgs/top-level/python-packages.nix
@@ -5684,20 +5684,20 @@ pythonPackages = modules // import ./python-packages-generated.nix {
 
 
   seqdiag = buildPythonPackage rec {
-    name = "seqdiag-0.8.2";
+    name = "seqdiag-0.9.0";
 
     src = fetchurl {
       url = "https://pypi.python.org/packages/source/s/seqdiag/${name}.tar.gz";
-      md5 = "61b3da29b5efaa89701b4db6d2d4d5fa";
+      md5 = "92946555ce219df18002e6c88b4055d3";
     };
 
     buildInputs = [ pep8 nose unittest2 docutils ];
 
     propagatedBuildInputs = [ blockdiag ];
 
-    # Some tests fail (because of missing input files?):
+    # Tests fail:
     #   ...
-    #   IOError: [Errno 2] No such file or directory: '/tmp/nix-build-python2.7-seqdiag-0.8.2.drv-0/seqdiag-0.8.2/src/seqdiag/tests/diagrams/separators.diag'
+    #   ERROR: Failure: OSError ([Errno 2] No such file or directory: '/tmp/nix-build-python2.7-seqdiag-0.9.0.drv-0/seqdiag-0.9.0/src/seqdiag/tests/diagrams/')
     doCheck = false;
 
     meta = with stdenv.lib; {