diff --git a/pkgs/development/python-modules/traitlets/default.nix b/pkgs/development/python-modules/traitlets/default.nix
index 0f18c669386..0342abdfefe 100644
--- a/pkgs/development/python-modules/traitlets/default.nix
+++ b/pkgs/development/python-modules/traitlets/default.nix
@@ -13,11 +13,11 @@
 
 buildPythonPackage rec {
   pname = "traitlets";
-  version = "4.3.2";
+  version = "4.3.3";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "9c4bd2d267b7153df9152698efb1050a5d84982d3384a37b2c1f7723ba3e7835";
+    sha256 = "d023ee369ddd2763310e4c3eae1ff649689440d4ae59d7485eb4cfbbe3e359f7";
   };
 
   checkInputs = [ glibcLocales pytest mock ];