diff --git a/ci/nur/combine.py b/ci/nur/combine.py
index 341b4e66e..68fbaa904 100644
--- a/ci/nur/combine.py
+++ b/ci/nur/combine.py
@@ -161,7 +161,7 @@ def setup_combined() -> None:
     manifest_lib = "lib"
     shutil.copytree(str(ROOT.joinpath("lib")), manifest_lib, symlinks=True, dirs_exist_ok=True)
     default_nix = "default.nix"
-    shutil.copy(ROOT.joinpath("default.nix"), default_nix, dirs_exist_ok=True)
+    shutil.copy(ROOT.joinpath("default.nix"), default_nix)
 
     vcs_files = [manifest_path, manifest_lib, default_nix]