diff --git a/pkgs/development/python-modules/json-schema-for-humans/default.nix b/pkgs/development/python-modules/json-schema-for-humans/default.nix
index 95edf974b7775..3ddc6fce10c31 100644
--- a/pkgs/development/python-modules/json-schema-for-humans/default.nix
+++ b/pkgs/development/python-modules/json-schema-for-humans/default.nix
@@ -19,7 +19,7 @@
 
 buildPythonPackage rec {
   pname = "json-schema-for-humans";
-  version = "1.0.3";
+  version = "1.3.0";
   pyproject = true;
 
   disabled = pythonOlder "3.7";
@@ -28,9 +28,14 @@ buildPythonPackage rec {
     owner = "coveooss";
     repo = "json-schema-for-humans";
     rev = "refs/tags/v${version}";
-    hash = "sha256-QMDbuiHfL8JLYJwceyxGR3Zc8+ZBVlCGHOBeH5x4BmQ=";
+    hash = "sha256-0nen6oJOWdihm/EWKSGQLlD70pRxezhCHykBJxlSFHo=";
   };
 
+  postPatch = ''
+    substituteInPlace pyproject.toml \
+      --replace-fail 'markdown2 = "^2.5.0"' 'markdown2 = "^2.4.1"'
+  '';
+
   pythonRelaxDeps = [ "dataclasses-json" ];
 
   build-system = [ poetry-core ];