diff --git a/pkgs/development/python-modules/zcs/default.nix b/pkgs/development/python-modules/zcs/default.nix
index 26a47a1f7698..453fbe43e4ce 100644
--- a/pkgs/development/python-modules/zcs/default.nix
+++ b/pkgs/development/python-modules/zcs/default.nix
@@ -8,11 +8,11 @@
 
 buildPythonPackage rec {
   pname = "zcs";
-  version = "0.1.18";
+  version = "0.1.21";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "sha256-cIg0LFQFVo91Ywvulxtx0/PPyQnRflJFnIi0gaUGGq4=";
+    sha256 = "sha256-Zs2aK+RR84uKjh+ZF/3gulS78zbb+XahTVSTJAArKHA=";
   };
 
   patches = [