diff --git a/pkgs/development/python-modules/cytoolz/default.nix b/pkgs/development/python-modules/cytoolz/default.nix
index 42305b455799..85b8c7a11e07 100644
--- a/pkgs/development/python-modules/cytoolz/default.nix
+++ b/pkgs/development/python-modules/cytoolz/default.nix
@@ -11,12 +11,12 @@
 
 buildPythonPackage rec {
   pname = "cytoolz";
-  version = "0.12.0";
+  version = "0.12.1";
   disabled = isPy27 || isPyPy;
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "sha256-wQWwX4XgP7zWAkQ3WWjmLkT+eYwVo1Mcki1TEBjSJBI=";
+    sha256 = "sha256-/DOQk5dIHJDePOyDG/uI2X4iDckZOdmWkgIC8YS0ZI4=";
   };
 
   nativeBuildInputs = [ cython ];