diff --git a/pkgs/development/python-modules/mailchecker/default.nix b/pkgs/development/python-modules/mailchecker/default.nix
index af96457afa4e..5d11aeb2bbb7 100644
--- a/pkgs/development/python-modules/mailchecker/default.nix
+++ b/pkgs/development/python-modules/mailchecker/default.nix
@@ -8,14 +8,14 @@
 
 buildPythonPackage rec {
   pname = "mailchecker";
-  version = "6.0.11";
+  version = "6.0.13";
   pyproject = true;
 
   disabled = pythonOlder "3.7";
 
   src = fetchPypi {
     inherit pname version;
-    hash = "sha256-vySQ4mo6msOFdgg44/zHMhpr4ZgP2tV0bQe2OgZHmqI=";
+    hash = "sha256-03Qew5vfLGkUFNw2Hg1nLwjiCkTXDNJy/QfiWc/bhjU=";
   };
 
   build-system = [ setuptools ];