diff --git a/pkgs/development/python-modules/materialx/default.nix b/pkgs/development/python-modules/materialx/default.nix
index b3ad7bbe0804..5d2c09dfef7f 100644
--- a/pkgs/development/python-modules/materialx/default.nix
+++ b/pkgs/development/python-modules/materialx/default.nix
@@ -64,6 +64,12 @@ buildPythonPackage rec {
     ln -s $out/python $target_dir
   '';
 
+  # Update to 1.39 has major API changes and downstream software
+  # needs to adapt, first. So, do not include in mass updates. For reference, see
+  # https://github.com/NixOS/nixpkgs/pull/326466#issuecomment-2293029160
+  # and https://github.com/NixOS/nixpkgs/issues/380230
+  passthru.skipBulkUpdate = true;
+
   meta = {
     changelog = "https://github.com/AcademySoftwareFoundation/MaterialX/blob/${src.rev}/CHANGELOG.md";
     description = "Open standard for representing rich material and look-development content in computer graphics";