diff --git a/pkgs/development/python-modules/readme_renderer/default.nix b/pkgs/development/python-modules/readme_renderer/default.nix
index ee2599a8fb75..f64faaf82ca7 100644
--- a/pkgs/development/python-modules/readme_renderer/default.nix
+++ b/pkgs/development/python-modules/readme_renderer/default.nix
@@ -4,7 +4,6 @@
 , cmarkgfm
 , docutils
 , fetchPypi
-, future
 , mock
 , pygments
 , pytestCheckHook
@@ -28,7 +27,6 @@ buildPythonPackage rec {
     bleach
     cmarkgfm
     docutils
-    future
     pygments
   ];
 
@@ -37,6 +35,11 @@ buildPythonPackage rec {
     pytestCheckHook
   ];
 
+  postPatch = ''
+    substituteInPlace setup.py \
+      --replace "cmarkgfm>=0.5.0,<0.7.0" "cmarkgfm>=0.5.0,<1"
+  '';
+
   pythonImportsCheck = [
     "readme_renderer"
   ];