diff --git a/pkgs/development/python-modules/railroad-diagrams/default.nix b/pkgs/development/python-modules/railroad-diagrams/default.nix
index 6d1a9eea6140..1af5a196250f 100644
--- a/pkgs/development/python-modules/railroad-diagrams/default.nix
+++ b/pkgs/development/python-modules/railroad-diagrams/default.nix
@@ -1,24 +1,30 @@
 { lib
 , buildPythonPackage
 , fetchPypi
+, pythonOlder
 }:
 
 buildPythonPackage rec {
   pname = "railroad-diagrams";
   version = "2.0.3";
+  format = "setuptools";
+
+  disabled = pythonOlder "3.7";
 
   src = fetchPypi {
     inherit pname version;
-    sha256 = "sha256-wRClrA4I/DWNw/hL5rowQMn0R61c6qiNg9Ho6nXqi+4=";
+    hash = "sha256-wRClrA4I/DWNw/hL5rowQMn0R61c6qiNg9Ho6nXqi+4=";
   };
 
-  # this is a dependency of pyparsing, which is a dependency of pytest
+  # This is a dependency of pyparsing, which is a dependency of pytest
   doCheck = false;
 
-  pythonImportsCheck = [ "railroad" ];
+  pythonImportsCheck = [
+    "railroad"
+  ];
 
   meta = with lib; {
-    description = "Generate SVG railroad syntax diagrams, like on JSON.org";
+    description = "Module to generate SVG railroad syntax diagrams";
     homepage = "https://github.com/tabatkins/railroad-diagrams";
     license = licenses.cc0;
     maintainers = with maintainers; [ jonringer ];