diff --git a/pkgs/development/python-modules/yangson/default.nix b/pkgs/development/python-modules/yangson/default.nix
index 80fa146f3d26..c623097a6d5f 100644
--- a/pkgs/development/python-modules/yangson/default.nix
+++ b/pkgs/development/python-modules/yangson/default.nix
@@ -11,18 +11,22 @@
 
 buildPythonPackage rec {
   pname = "yangson";
-  version = "1.5.2";
+  version = "1.5.6";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "CZ-NIC";
     repo = "yangson";
     rev = "refs/tags/${version}";
-    hash = "sha256-c/UWyfJdVz6wSluL1Ej9cSV3EpDUTkP0GTeHPYfAduE=";
+    hash = "sha256-/9MxCkcPGRNZkuwAAvlr7gtGcyxXtliski7bNtFhVBE=";
   };
 
   build-system = [ poetry-core ];
 
+  pythonRelaxDeps = [
+    "setuptools"
+  ];
+
   dependencies = [
     elementpath
     pyyaml