diff --git a/pkgs/development/python-modules/fastjet/default.nix b/pkgs/development/python-modules/fastjet/default.nix
index 54ebfea342a6..73830c7d5339 100644
--- a/pkgs/development/python-modules/fastjet/default.nix
+++ b/pkgs/development/python-modules/fastjet/default.nix
@@ -33,13 +33,13 @@ in
 
 buildPythonPackage rec {
   pname = "fastjet";
-  version = "3.4.2.1";
+  version = "3.4.3.1";
   pyproject = true;
 
   src = fetchPypi {
     pname = "fastjet";
     inherit version;
-    hash = "sha256-YlYJWCdwEBiG+koh1X2app1HinvktryisxP/C024g1k=";
+    hash = "sha256-c9LE3axkm3tJt6RfHHIbJZsA/0s2Cl1UqxGKqKvospI=";
   };
 
   # unvendor fastjet/fastjet-contrib