diff --git a/pkgs/development/python-modules/app-model/default.nix b/pkgs/development/python-modules/app-model/default.nix
index 29d5d3e2a142..8f0a36b3ce13 100644
--- a/pkgs/development/python-modules/app-model/default.nix
+++ b/pkgs/development/python-modules/app-model/default.nix
@@ -12,16 +12,16 @@
   typing-extensions,
 }:
 
-buildPythonPackage rec {
+buildPythonPackage (finalAttrs: {
   pname = "app-model";
-  version = "0.4.0";
+  version = "0.5.1";
   pyproject = true;
 
   src = fetchFromGitHub {
     owner = "pyapp-kit";
     repo = "app-model";
-    tag = "v${version}";
-    hash = "sha256-T7aUwdne1rUzhVRotlxDvEBm3mi/frUQziZdLo53Lsg=";
+    tag = "v${finalAttrs.version}";
+    hash = "sha256-zKaCxozT6OOPfrXMDic5d5DMb/I9tTiJFlX21Cc1yjY=";
   };
 
   build-system = [
@@ -44,8 +44,8 @@ buildPythonPackage rec {
   meta = {
     description = "Module to implement generic application schema";
     homepage = "https://github.com/pyapp-kit/app-model";
-    changelog = "https://github.com/pyapp-kit/app-model/blob/${src.tag}/CHANGELOG.md";
+    changelog = "https://github.com/pyapp-kit/app-model/blob/${finalAttrs.src.tag}/CHANGELOG.md";
     license = lib.licenses.bsd3;
     maintainers = with lib.maintainers; [ fab ];
   };
-}
+})