diff --git a/pkgs/development/python-modules/gaphas/default.nix b/pkgs/development/python-modules/gaphas/default.nix
index f0080b8b170f..7566ea814eec 100644
--- a/pkgs/development/python-modules/gaphas/default.nix
+++ b/pkgs/development/python-modules/gaphas/default.nix
@@ -13,20 +13,23 @@
 buildPythonPackage rec {
   pname = "gaphas";
   version = "3.9.2";
-  disabled = pythonOlder "3.7";
-
   format = "pyproject";
 
+  disabled = pythonOlder "3.7";
+
   src = fetchPypi {
     inherit pname version;
-    sha256 = "sha256-hw8aGjsrx6xWPbFybpss5EB3eg6tmxgkXpGiWguLKP4=";
+    hash = "sha256-hw8aGjsrx6xWPbFybpss5EB3eg6tmxgkXpGiWguLKP4=";
   };
 
   nativeBuildInputs = [
     poetry-core
   ];
 
-  buildInputs = [ gobject-introspection gtk3 ];
+  buildInputs = [
+    gobject-introspection
+    gtk3
+  ];
 
   propagatedBuildInputs = [
     pycairo
@@ -34,12 +37,15 @@ buildPythonPackage rec {
     typing-extensions
   ];
 
-  pythonImportsCheck = [ "gaphas" ];
+  pythonImportsCheck = [
+    "gaphas"
+  ];
 
   meta = with lib; {
     description = "GTK+ based diagramming widget";
-    maintainers = with maintainers; [ wolfangaukang ];
     homepage = "https://github.com/gaphor/gaphas";
+    changelog = "https://github.com/gaphor/gaphas/releases/tag/${version}";
     license = licenses.asl20;
+    maintainers = with maintainers; [ wolfangaukang ];
   };
 }