diff --git a/pkgs/development/python-modules/mandown/default.nix b/pkgs/development/python-modules/mandown/default.nix
index 51d7db72259b..f5cfc39bc2cd 100644
--- a/pkgs/development/python-modules/mandown/default.nix
+++ b/pkgs/development/python-modules/mandown/default.nix
@@ -2,6 +2,7 @@
 , buildPythonPackage
 , fetchFromGitHub
 , poetry-core
+, pythonRelaxDepsHook
 , beautifulsoup4
 , comicon
 , feedparser
@@ -18,7 +19,7 @@
 buildPythonPackage rec {
   pname = "mandown";
   version = "1.7.0";
-  format = "pyproject";
+  pyproject = true;
 
   src = fetchFromGitHub {
     owner = "potatoeggy";
@@ -29,6 +30,12 @@ buildPythonPackage rec {
 
   nativeBuildInputs = [
     poetry-core
+    pythonRelaxDepsHook
+  ];
+
+  pythonRelaxDeps = [
+    "pillow"
+    "typer"
   ];
 
   propagatedBuildInputs = [
@@ -50,10 +57,6 @@ buildPythonPackage rec {
     ];
   };
 
-  postPatch = ''
-    substituteInPlace pyproject.toml --replace 'typer = "^0.7.0"' 'typer = "^0"'
-  '';
-
   pythonImportsCheck = [ "mandown" ];
 
   meta = with lib; {