diff --git a/pkgs/by-name/pd/pdfposter/package.nix b/pkgs/by-name/pd/pdfposter/package.nix
index f4f36d3291f7..e241327cf2de 100644
--- a/pkgs/by-name/pd/pdfposter/package.nix
+++ b/pkgs/by-name/pd/pdfposter/package.nix
@@ -12,6 +12,7 @@ let
       pypdf2 = super.pypdf2.overridePythonAttrs (oldAttrs: rec {
         version = "2.11.1";
         format = "setuptools";
+        pyproject = null;
         src = fetchPypi {
           pname = "PyPDF2";
           inherit version;